| //! Type inference for expressions. |
| |
| use std::{ |
| iter::{repeat, repeat_with}, |
| mem, |
| sync::Arc, |
| }; |
| |
| use chalk_ir::{cast::Cast, fold::Shift, Mutability, TyVariableKind}; |
| use hir_def::{ |
| expr::{ |
| ArithOp, Array, BinaryOp, CmpOp, Expr, ExprId, Literal, MatchGuard, Ordering, Statement, |
| UnaryOp, |
| }, |
| path::{GenericArg, GenericArgs}, |
| resolver::resolver_for_expr, |
| AssocContainerId, FieldId, FunctionId, Lookup, |
| }; |
| use hir_expand::name::{name, Name}; |
| use stdx::always; |
| use syntax::ast::RangeOp; |
| |
| use crate::{ |
| autoderef::{self, Autoderef}, |
| consteval, |
| infer::coerce::CoerceMany, |
| lower::lower_to_chalk_mutability, |
| mapping::from_chalk, |
| method_resolution, |
| primitive::{self, UintTy}, |
| static_lifetime, to_chalk_trait_id, |
| traits::FnTrait, |
| utils::{generics, Generics}, |
| AdtId, Binders, CallableDefId, FnPointer, FnSig, FnSubst, InEnvironment, Interner, |
| ProjectionTyExt, Rawness, Scalar, Substitution, TraitRef, Ty, TyBuilder, TyExt, TyKind, |
| }; |
| |
| use super::{ |
| find_breakable, BindingMode, BreakableContext, Diverges, Expectation, InferenceContext, |
| InferenceDiagnostic, TypeMismatch, |
| }; |
| |
| impl<'a> InferenceContext<'a> { |
| pub(super) fn infer_expr(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { |
| let ty = self.infer_expr_inner(tgt_expr, expected); |
| if self.resolve_ty_shallow(&ty).is_never() { |
| // Any expression that produces a value of type `!` must have diverged |
| self.diverges = Diverges::Always; |
| } |
| if let Some(expected_ty) = expected.only_has_type(&mut self.table) { |
| let could_unify = self.unify(&ty, &expected_ty); |
| if !could_unify { |
| self.result.type_mismatches.insert( |
| tgt_expr.into(), |
| TypeMismatch { expected: expected_ty, actual: ty.clone() }, |
| ); |
| } |
| } |
| ty |
| } |
| |
| /// Infer type of expression with possibly implicit coerce to the expected type. |
| /// Return the type after possible coercion. |
| pub(super) fn infer_expr_coerce(&mut self, expr: ExprId, expected: &Expectation) -> Ty { |
| let ty = self.infer_expr_inner(expr, expected); |
| let ty = if let Some(target) = expected.only_has_type(&mut self.table) { |
| match self.coerce(Some(expr), &ty, &target) { |
| Ok(res) => res.value, |
| Err(_) => { |
| self.result |
| .type_mismatches |
| .insert(expr.into(), TypeMismatch { expected: target, actual: ty.clone() }); |
| // Return actual type when type mismatch. |
| // This is needed for diagnostic when return type mismatch. |
| ty |
| } |
| } |
| } else { |
| ty |
| }; |
| |
| ty |
| } |
| |
| fn callable_sig_from_fn_trait(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> { |
| let krate = self.resolver.krate()?; |
| let fn_once_trait = FnTrait::FnOnce.get_id(self.db, krate)?; |
| let output_assoc_type = |
| self.db.trait_data(fn_once_trait).associated_type_by_name(&name![Output])?; |
| |
| let mut arg_tys = vec![]; |
| let arg_ty = TyBuilder::tuple(num_args) |
| .fill(repeat_with(|| { |
| let arg = self.table.new_type_var(); |
| arg_tys.push(arg.clone()); |
| arg |
| })) |
| .build(); |
| |
| let projection = { |
| let b = TyBuilder::assoc_type_projection(self.db, output_assoc_type); |
| if b.remaining() != 2 { |
| return None; |
| } |
| b.push(ty.clone()).push(arg_ty).build() |
| }; |
| |
| let trait_env = self.trait_env.env.clone(); |
| let obligation = InEnvironment { |
| goal: projection.trait_ref(self.db).cast(&Interner), |
| environment: trait_env, |
| }; |
| let canonical = self.canonicalize(obligation.clone()); |
| if self.db.trait_solve(krate, canonical.value.cast(&Interner)).is_some() { |
| self.push_obligation(obligation.goal); |
| let return_ty = self.table.normalize_projection_ty(projection); |
| Some((arg_tys, return_ty)) |
| } else { |
| None |
| } |
| } |
| |
| pub(crate) fn callable_sig(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec<Ty>, Ty)> { |
| match ty.callable_sig(self.db) { |
| Some(sig) => Some((sig.params().to_vec(), sig.ret().clone())), |
| None => self.callable_sig_from_fn_trait(ty, num_args), |
| } |
| } |
| |
| fn infer_expr_inner(&mut self, tgt_expr: ExprId, expected: &Expectation) -> Ty { |
| self.db.unwind_if_cancelled(); |
| |
| let body = Arc::clone(&self.body); // avoid borrow checker problem |
| let ty = match &body[tgt_expr] { |
| Expr::Missing => self.err_ty(), |
| &Expr::If { condition, then_branch, else_branch } => { |
| // if let is desugared to match, so this is always simple if |
| self.infer_expr( |
| condition, |
| &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(&Interner)), |
| ); |
| |
| let condition_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); |
| let mut both_arms_diverge = Diverges::Always; |
| |
| let result_ty = self.table.new_type_var(); |
| let then_ty = self.infer_expr_inner(then_branch, expected); |
| both_arms_diverge &= mem::replace(&mut self.diverges, Diverges::Maybe); |
| let mut coerce = CoerceMany::new(result_ty); |
| coerce.coerce(self, Some(then_branch), &then_ty); |
| let else_ty = match else_branch { |
| Some(else_branch) => self.infer_expr_inner(else_branch, expected), |
| None => TyBuilder::unit(), |
| }; |
| both_arms_diverge &= self.diverges; |
| // FIXME: create a synthetic `else {}` so we have something to refer to here instead of None? |
| coerce.coerce(self, else_branch, &else_ty); |
| |
| self.diverges = condition_diverges | both_arms_diverge; |
| |
| coerce.complete() |
| } |
| Expr::Block { statements, tail, label, id: _ } => { |
| let old_resolver = mem::replace( |
| &mut self.resolver, |
| resolver_for_expr(self.db.upcast(), self.owner, tgt_expr), |
| ); |
| let ty = match label { |
| Some(_) => { |
| let break_ty = self.table.new_type_var(); |
| self.breakables.push(BreakableContext { |
| may_break: false, |
| coerce: CoerceMany::new(break_ty.clone()), |
| label: label.map(|label| self.body[label].name.clone()), |
| }); |
| let ty = self.infer_block( |
| tgt_expr, |
| statements, |
| *tail, |
| &Expectation::has_type(break_ty), |
| ); |
| let ctxt = self.breakables.pop().expect("breakable stack broken"); |
| if ctxt.may_break { |
| ctxt.coerce.complete() |
| } else { |
| ty |
| } |
| } |
| None => self.infer_block(tgt_expr, statements, *tail, expected), |
| }; |
| self.resolver = old_resolver; |
| ty |
| } |
| Expr::Unsafe { body } | Expr::Const { body } => self.infer_expr(*body, expected), |
| Expr::TryBlock { body } => { |
| let _inner = self.infer_expr(*body, expected); |
| // FIXME should be std::result::Result<{inner}, _> |
| self.err_ty() |
| } |
| Expr::Async { body } => { |
| // Use the first type parameter as the output type of future. |
| // existential type AsyncBlockImplTrait<InnerType>: Future<Output = InnerType> |
| let inner_ty = self.infer_expr(*body, &Expectation::none()); |
| let impl_trait_id = crate::ImplTraitId::AsyncBlockTypeImplTrait(self.owner, *body); |
| let opaque_ty_id = self.db.intern_impl_trait_id(impl_trait_id).into(); |
| TyKind::OpaqueType(opaque_ty_id, Substitution::from1(&Interner, inner_ty)) |
| .intern(&Interner) |
| } |
| Expr::Loop { body, label } => { |
| self.breakables.push(BreakableContext { |
| may_break: false, |
| coerce: CoerceMany::new(self.table.new_type_var()), |
| label: label.map(|label| self.body[label].name.clone()), |
| }); |
| self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit())); |
| |
| let ctxt = self.breakables.pop().expect("breakable stack broken"); |
| |
| if ctxt.may_break { |
| self.diverges = Diverges::Maybe; |
| ctxt.coerce.complete() |
| } else { |
| TyKind::Never.intern(&Interner) |
| } |
| } |
| Expr::While { condition, body, label } => { |
| self.breakables.push(BreakableContext { |
| may_break: false, |
| coerce: CoerceMany::new(self.err_ty()), |
| label: label.map(|label| self.body[label].name.clone()), |
| }); |
| // while let is desugared to a match loop, so this is always simple while |
| self.infer_expr( |
| *condition, |
| &Expectation::has_type(TyKind::Scalar(Scalar::Bool).intern(&Interner)), |
| ); |
| self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit())); |
| let _ctxt = self.breakables.pop().expect("breakable stack broken"); |
| // the body may not run, so it diverging doesn't mean we diverge |
| self.diverges = Diverges::Maybe; |
| TyBuilder::unit() |
| } |
| Expr::For { iterable, body, pat, label } => { |
| let iterable_ty = self.infer_expr(*iterable, &Expectation::none()); |
| |
| self.breakables.push(BreakableContext { |
| may_break: false, |
| coerce: CoerceMany::new(self.err_ty()), |
| label: label.map(|label| self.body[label].name.clone()), |
| }); |
| let pat_ty = |
| self.resolve_associated_type(iterable_ty, self.resolve_into_iter_item()); |
| |
| self.infer_pat(*pat, &pat_ty, BindingMode::default()); |
| |
| self.infer_expr(*body, &Expectation::has_type(TyBuilder::unit())); |
| let _ctxt = self.breakables.pop().expect("breakable stack broken"); |
| // the body may not run, so it diverging doesn't mean we diverge |
| self.diverges = Diverges::Maybe; |
| TyBuilder::unit() |
| } |
| Expr::Lambda { body, args, ret_type, arg_types } => { |
| assert_eq!(args.len(), arg_types.len()); |
| |
| let mut sig_tys = Vec::new(); |
| |
| // collect explicitly written argument types |
| for arg_type in arg_types.iter() { |
| let arg_ty = if let Some(type_ref) = arg_type { |
| self.make_ty(type_ref) |
| } else { |
| self.table.new_type_var() |
| }; |
| sig_tys.push(arg_ty); |
| } |
| |
| // add return type |
| let ret_ty = match ret_type { |
| Some(type_ref) => self.make_ty(type_ref), |
| None => self.table.new_type_var(), |
| }; |
| sig_tys.push(ret_ty.clone()); |
| let sig_ty = TyKind::Function(FnPointer { |
| num_binders: 0, |
| sig: FnSig { abi: (), safety: chalk_ir::Safety::Safe, variadic: false }, |
| substitution: FnSubst( |
| Substitution::from_iter(&Interner, sig_tys.clone()).shifted_in(&Interner), |
| ), |
| }) |
| .intern(&Interner); |
| let closure_id = self.db.intern_closure((self.owner, tgt_expr)).into(); |
| let closure_ty = |
| TyKind::Closure(closure_id, Substitution::from1(&Interner, sig_ty.clone())) |
| .intern(&Interner); |
| |
| // Eagerly try to relate the closure type with the expected |
| // type, otherwise we often won't have enough information to |
| // infer the body. |
| self.deduce_closure_type_from_expectations( |
| tgt_expr, |
| &closure_ty, |
| &sig_ty, |
| expected, |
| ); |
| |
| // Now go through the argument patterns |
| for (arg_pat, arg_ty) in args.iter().zip(sig_tys) { |
| self.infer_pat(*arg_pat, &arg_ty, BindingMode::default()); |
| } |
| |
| let prev_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); |
| let prev_ret_ty = mem::replace(&mut self.return_ty, ret_ty.clone()); |
| |
| self.infer_expr_coerce(*body, &Expectation::has_type(ret_ty)); |
| |
| self.diverges = prev_diverges; |
| self.return_ty = prev_ret_ty; |
| |
| closure_ty |
| } |
| Expr::Call { callee, args } => { |
| let callee_ty = self.infer_expr(*callee, &Expectation::none()); |
| let canonicalized = self.canonicalize(callee_ty.clone()); |
| let mut derefs = Autoderef::new( |
| self.db, |
| self.resolver.krate(), |
| InEnvironment { |
| goal: canonicalized.value.clone(), |
| environment: self.table.trait_env.env.clone(), |
| }, |
| ); |
| let res = derefs.by_ref().find_map(|(callee_deref_ty, _)| { |
| self.callable_sig( |
| &canonicalized.decanonicalize_ty(callee_deref_ty.value), |
| args.len(), |
| ) |
| }); |
| let (param_tys, ret_ty): (Vec<Ty>, Ty) = match res { |
| Some(res) => { |
| self.write_expr_adj(*callee, self.auto_deref_adjust_steps(&derefs)); |
| res |
| } |
| None => (Vec::new(), self.err_ty()), |
| }; |
| self.register_obligations_for_call(&callee_ty); |
| |
| let expected_inputs = self.expected_inputs_for_expected_output( |
| expected, |
| ret_ty.clone(), |
| param_tys.clone(), |
| ); |
| |
| self.check_call_arguments(args, &expected_inputs, ¶m_tys); |
| self.normalize_associated_types_in(ret_ty) |
| } |
| Expr::MethodCall { receiver, args, method_name, generic_args } => self |
| .infer_method_call( |
| tgt_expr, |
| *receiver, |
| args, |
| method_name, |
| generic_args.as_deref(), |
| expected, |
| ), |
| Expr::Match { expr, arms } => { |
| let input_ty = self.infer_expr(*expr, &Expectation::none()); |
| |
| let expected = expected.adjust_for_branches(&mut self.table); |
| |
| let result_ty = if arms.is_empty() { |
| TyKind::Never.intern(&Interner) |
| } else { |
| match &expected { |
| Expectation::HasType(ty) => ty.clone(), |
| _ => self.table.new_type_var(), |
| } |
| }; |
| let mut coerce = CoerceMany::new(result_ty); |
| |
| let matchee_diverges = self.diverges; |
| let mut all_arms_diverge = Diverges::Always; |
| |
| for arm in arms { |
| self.diverges = Diverges::Maybe; |
| let _pat_ty = self.infer_pat(arm.pat, &input_ty, BindingMode::default()); |
| match arm.guard { |
| Some(MatchGuard::If { expr: guard_expr }) => { |
| self.infer_expr( |
| guard_expr, |
| &Expectation::has_type( |
| TyKind::Scalar(Scalar::Bool).intern(&Interner), |
| ), |
| ); |
| } |
| Some(MatchGuard::IfLet { expr, pat }) => { |
| let input_ty = self.infer_expr(expr, &Expectation::none()); |
| let _pat_ty = self.infer_pat(pat, &input_ty, BindingMode::default()); |
| } |
| _ => {} |
| } |
| |
| let arm_ty = self.infer_expr_inner(arm.expr, &expected); |
| all_arms_diverge &= self.diverges; |
| coerce.coerce(self, Some(arm.expr), &arm_ty); |
| } |
| |
| self.diverges = matchee_diverges | all_arms_diverge; |
| |
| coerce.complete() |
| } |
| Expr::Path(p) => { |
| // FIXME this could be more efficient... |
| let resolver = resolver_for_expr(self.db.upcast(), self.owner, tgt_expr); |
| self.infer_path(&resolver, p, tgt_expr.into()).unwrap_or_else(|| self.err_ty()) |
| } |
| Expr::Continue { .. } => TyKind::Never.intern(&Interner), |
| Expr::Break { expr, label } => { |
| let mut coerce = match find_breakable(&mut self.breakables, label.as_ref()) { |
| Some(ctxt) => { |
| // avoiding the borrowck |
| mem::replace( |
| &mut ctxt.coerce, |
| CoerceMany::new(self.result.standard_types.unknown.clone()), |
| ) |
| } |
| None => CoerceMany::new(self.result.standard_types.unknown.clone()), |
| }; |
| |
| let val_ty = if let Some(expr) = *expr { |
| self.infer_expr(expr, &Expectation::none()) |
| } else { |
| TyBuilder::unit() |
| }; |
| |
| // FIXME: create a synthetic `()` during lowering so we have something to refer to here? |
| coerce.coerce(self, *expr, &val_ty); |
| |
| if let Some(ctxt) = find_breakable(&mut self.breakables, label.as_ref()) { |
| ctxt.coerce = coerce; |
| ctxt.may_break = true; |
| } else { |
| self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop { |
| expr: tgt_expr, |
| }); |
| }; |
| |
| TyKind::Never.intern(&Interner) |
| } |
| Expr::Return { expr } => { |
| if let Some(expr) = expr { |
| self.infer_expr_coerce(*expr, &Expectation::has_type(self.return_ty.clone())); |
| } else { |
| let unit = TyBuilder::unit(); |
| let _ = self.coerce(Some(tgt_expr), &unit, &self.return_ty.clone()); |
| } |
| TyKind::Never.intern(&Interner) |
| } |
| Expr::Yield { expr } => { |
| // FIXME: track yield type for coercion |
| if let Some(expr) = expr { |
| self.infer_expr(*expr, &Expectation::none()); |
| } |
| TyKind::Never.intern(&Interner) |
| } |
| Expr::RecordLit { path, fields, spread } => { |
| let (ty, def_id) = self.resolve_variant(path.as_deref(), false); |
| if let Some(variant) = def_id { |
| self.write_variant_resolution(tgt_expr.into(), variant); |
| } |
| |
| if let Some(t) = expected.only_has_type(&mut self.table) { |
| self.unify(&ty, &t); |
| } |
| |
| let substs = ty |
| .as_adt() |
| .map(|(_, s)| s.clone()) |
| .unwrap_or_else(|| Substitution::empty(&Interner)); |
| let field_types = def_id.map(|it| self.db.field_types(it)).unwrap_or_default(); |
| let variant_data = def_id.map(|it| it.variant_data(self.db.upcast())); |
| for field in fields.iter() { |
| let field_def = |
| variant_data.as_ref().and_then(|it| match it.field(&field.name) { |
| Some(local_id) => Some(FieldId { parent: def_id.unwrap(), local_id }), |
| None => { |
| self.push_diagnostic(InferenceDiagnostic::NoSuchField { |
| expr: field.expr, |
| }); |
| None |
| } |
| }); |
| let field_ty = field_def.map_or(self.err_ty(), |it| { |
| field_types[it.local_id].clone().substitute(&Interner, &substs) |
| }); |
| self.infer_expr_coerce(field.expr, &Expectation::has_type(field_ty)); |
| } |
| if let Some(expr) = spread { |
| self.infer_expr(*expr, &Expectation::has_type(ty.clone())); |
| } |
| ty |
| } |
| Expr::Field { expr, name } => { |
| let receiver_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| let canonicalized = self.canonicalize(receiver_ty); |
| |
| let mut autoderef = Autoderef::new( |
| self.db, |
| self.resolver.krate(), |
| InEnvironment { |
| goal: canonicalized.value.clone(), |
| environment: self.trait_env.env.clone(), |
| }, |
| ); |
| let ty = autoderef.by_ref().find_map(|(derefed_ty, _)| { |
| let def_db = self.db.upcast(); |
| let module = self.resolver.module(); |
| let is_visible = |field_id: &FieldId| { |
| module |
| .map(|mod_id| { |
| self.db.field_visibilities(field_id.parent)[field_id.local_id] |
| .is_visible_from(def_db, mod_id) |
| }) |
| .unwrap_or(true) |
| }; |
| match canonicalized.decanonicalize_ty(derefed_ty.value).kind(&Interner) { |
| TyKind::Tuple(_, substs) => name.as_tuple_index().and_then(|idx| { |
| substs |
| .as_slice(&Interner) |
| .get(idx) |
| .map(|a| a.assert_ty_ref(&Interner)) |
| .cloned() |
| }), |
| TyKind::Adt(AdtId(hir_def::AdtId::StructId(s)), parameters) => { |
| let local_id = self.db.struct_data(*s).variant_data.field(name)?; |
| let field = FieldId { parent: (*s).into(), local_id }; |
| if is_visible(&field) { |
| self.write_field_resolution(tgt_expr, field); |
| Some( |
| self.db.field_types((*s).into())[field.local_id] |
| .clone() |
| .substitute(&Interner, ¶meters), |
| ) |
| } else { |
| None |
| } |
| } |
| TyKind::Adt(AdtId(hir_def::AdtId::UnionId(u)), parameters) => { |
| let local_id = self.db.union_data(*u).variant_data.field(name)?; |
| let field = FieldId { parent: (*u).into(), local_id }; |
| if is_visible(&field) { |
| self.write_field_resolution(tgt_expr, field); |
| Some( |
| self.db.field_types((*u).into())[field.local_id] |
| .clone() |
| .substitute(&Interner, ¶meters), |
| ) |
| } else { |
| None |
| } |
| } |
| _ => None, |
| } |
| }); |
| let ty = match ty { |
| Some(ty) => { |
| self.write_expr_adj(*expr, self.auto_deref_adjust_steps(&autoderef)); |
| ty |
| } |
| None => self.err_ty(), |
| }; |
| let ty = self.insert_type_vars(ty); |
| self.normalize_associated_types_in(ty) |
| } |
| Expr::Await { expr } => { |
| let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| self.resolve_associated_type(inner_ty, self.resolve_future_future_output()) |
| } |
| Expr::Try { expr } => { |
| let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| self.resolve_associated_type(inner_ty, self.resolve_ops_try_ok()) |
| } |
| Expr::Cast { expr, type_ref } => { |
| // FIXME: propagate the "castable to" expectation (and find a test case that shows this is necessary) |
| let _inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| let cast_ty = self.make_ty(type_ref); |
| // FIXME check the cast... |
| cast_ty |
| } |
| Expr::Ref { expr, rawness, mutability } => { |
| let mutability = lower_to_chalk_mutability(*mutability); |
| let expectation = if let Some((exp_inner, exp_rawness, exp_mutability)) = expected |
| .only_has_type(&mut self.table) |
| .as_ref() |
| .and_then(|t| t.as_reference_or_ptr()) |
| { |
| if exp_mutability == Mutability::Mut && mutability == Mutability::Not { |
| // FIXME: record type error - expected mut reference but found shared ref, |
| // which cannot be coerced |
| } |
| if exp_rawness == Rawness::Ref && *rawness == Rawness::RawPtr { |
| // FIXME: record type error - expected reference but found ptr, |
| // which cannot be coerced |
| } |
| Expectation::rvalue_hint(&mut self.table, Ty::clone(exp_inner)) |
| } else { |
| Expectation::none() |
| }; |
| let inner_ty = self.infer_expr_inner(*expr, &expectation); |
| match rawness { |
| Rawness::RawPtr => TyKind::Raw(mutability, inner_ty), |
| Rawness::Ref => TyKind::Ref(mutability, static_lifetime(), inner_ty), |
| } |
| .intern(&Interner) |
| } |
| Expr::Box { expr } => { |
| let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| if let Some(box_) = self.resolve_boxed_box() { |
| TyBuilder::adt(self.db, box_) |
| .push(inner_ty) |
| .fill_with_defaults(self.db, || self.table.new_type_var()) |
| .build() |
| } else { |
| self.err_ty() |
| } |
| } |
| Expr::UnaryOp { expr, op } => { |
| let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); |
| let inner_ty = self.resolve_ty_shallow(&inner_ty); |
| match op { |
| UnaryOp::Deref => match self.resolver.krate() { |
| Some(krate) => { |
| let canonicalized = self.canonicalize(inner_ty); |
| match autoderef::deref( |
| self.db, |
| krate, |
| InEnvironment { |
| goal: &canonicalized.value, |
| environment: self.trait_env.env.clone(), |
| }, |
| ) { |
| Some(derefed_ty) => { |
| canonicalized.decanonicalize_ty(derefed_ty.value) |
| } |
| None => self.err_ty(), |
| } |
| } |
| None => self.err_ty(), |
| }, |
| UnaryOp::Neg => { |
| match inner_ty.kind(&Interner) { |
| // Fast path for builtins |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_) | Scalar::Float(_)) |
| | TyKind::InferenceVar( |
| _, |
| TyVariableKind::Integer | TyVariableKind::Float, |
| ) => inner_ty, |
| // Otherwise we resolve via the std::ops::Neg trait |
| _ => self |
| .resolve_associated_type(inner_ty, self.resolve_ops_neg_output()), |
| } |
| } |
| UnaryOp::Not => { |
| match inner_ty.kind(&Interner) { |
| // Fast path for builtins |
| TyKind::Scalar(Scalar::Bool | Scalar::Int(_) | Scalar::Uint(_)) |
| | TyKind::InferenceVar(_, TyVariableKind::Integer) => inner_ty, |
| // Otherwise we resolve via the std::ops::Not trait |
| _ => self |
| .resolve_associated_type(inner_ty, self.resolve_ops_not_output()), |
| } |
| } |
| } |
| } |
| Expr::BinaryOp { lhs, rhs, op } => match op { |
| Some(BinaryOp::Assignment { op: None }) => { |
| let lhs_ty = self.infer_expr(*lhs, &Expectation::none()); |
| self.infer_expr_coerce(*rhs, &Expectation::has_type(lhs_ty)); |
| self.result.standard_types.unit.clone() |
| } |
| Some(BinaryOp::LogicOp(_)) => { |
| let bool_ty = self.result.standard_types.bool_.clone(); |
| self.infer_expr_coerce(*lhs, &Expectation::HasType(bool_ty.clone())); |
| let lhs_diverges = self.diverges; |
| self.infer_expr_coerce(*rhs, &Expectation::HasType(bool_ty.clone())); |
| // Depending on the LHS' value, the RHS can never execute. |
| self.diverges = lhs_diverges; |
| bool_ty |
| } |
| Some(op) => self.infer_overloadable_binop(*lhs, *op, *rhs, tgt_expr), |
| _ => self.err_ty(), |
| }, |
| Expr::Range { lhs, rhs, range_type } => { |
| let lhs_ty = lhs.map(|e| self.infer_expr_inner(e, &Expectation::none())); |
| let rhs_expect = lhs_ty |
| .as_ref() |
| .map_or_else(Expectation::none, |ty| Expectation::has_type(ty.clone())); |
| let rhs_ty = rhs.map(|e| self.infer_expr(e, &rhs_expect)); |
| match (range_type, lhs_ty, rhs_ty) { |
| (RangeOp::Exclusive, None, None) => match self.resolve_range_full() { |
| Some(adt) => TyBuilder::adt(self.db, adt).build(), |
| None => self.err_ty(), |
| }, |
| (RangeOp::Exclusive, None, Some(ty)) => match self.resolve_range_to() { |
| Some(adt) => TyBuilder::adt(self.db, adt).push(ty).build(), |
| None => self.err_ty(), |
| }, |
| (RangeOp::Inclusive, None, Some(ty)) => { |
| match self.resolve_range_to_inclusive() { |
| Some(adt) => TyBuilder::adt(self.db, adt).push(ty).build(), |
| None => self.err_ty(), |
| } |
| } |
| (RangeOp::Exclusive, Some(_), Some(ty)) => match self.resolve_range() { |
| Some(adt) => TyBuilder::adt(self.db, adt).push(ty).build(), |
| None => self.err_ty(), |
| }, |
| (RangeOp::Inclusive, Some(_), Some(ty)) => { |
| match self.resolve_range_inclusive() { |
| Some(adt) => TyBuilder::adt(self.db, adt).push(ty).build(), |
| None => self.err_ty(), |
| } |
| } |
| (RangeOp::Exclusive, Some(ty), None) => match self.resolve_range_from() { |
| Some(adt) => TyBuilder::adt(self.db, adt).push(ty).build(), |
| None => self.err_ty(), |
| }, |
| (RangeOp::Inclusive, _, None) => self.err_ty(), |
| } |
| } |
| Expr::Index { base, index } => { |
| let base_ty = self.infer_expr_inner(*base, &Expectation::none()); |
| let index_ty = self.infer_expr(*index, &Expectation::none()); |
| |
| if let (Some(index_trait), Some(krate)) = |
| (self.resolve_ops_index(), self.resolver.krate()) |
| { |
| let canonicalized = self.canonicalize(base_ty); |
| let self_ty = method_resolution::resolve_indexing_op( |
| self.db, |
| &canonicalized.value, |
| self.trait_env.clone(), |
| krate, |
| index_trait, |
| ); |
| let self_ty = |
| self_ty.map_or(self.err_ty(), |t| canonicalized.decanonicalize_ty(t.value)); |
| self.resolve_associated_type_with_params( |
| self_ty, |
| self.resolve_ops_index_output(), |
| &[index_ty], |
| ) |
| } else { |
| self.err_ty() |
| } |
| } |
| Expr::Tuple { exprs } => { |
| let mut tys = match expected |
| .only_has_type(&mut self.table) |
| .as_ref() |
| .map(|t| t.kind(&Interner)) |
| { |
| Some(TyKind::Tuple(_, substs)) => substs |
| .iter(&Interner) |
| .map(|a| a.assert_ty_ref(&Interner).clone()) |
| .chain(repeat_with(|| self.table.new_type_var())) |
| .take(exprs.len()) |
| .collect::<Vec<_>>(), |
| _ => (0..exprs.len()).map(|_| self.table.new_type_var()).collect(), |
| }; |
| |
| for (expr, ty) in exprs.iter().zip(tys.iter_mut()) { |
| self.infer_expr_coerce(*expr, &Expectation::has_type(ty.clone())); |
| } |
| |
| TyKind::Tuple(tys.len(), Substitution::from_iter(&Interner, tys)).intern(&Interner) |
| } |
| Expr::Array(array) => { |
| let elem_ty = |
| match expected.to_option(&mut self.table).as_ref().map(|t| t.kind(&Interner)) { |
| Some(TyKind::Array(st, _) | TyKind::Slice(st)) => st.clone(), |
| _ => self.table.new_type_var(), |
| }; |
| let mut coerce = CoerceMany::new(elem_ty.clone()); |
| |
| let expected = Expectation::has_type(elem_ty.clone()); |
| let len = match array { |
| Array::ElementList(items) => { |
| for &expr in items.iter() { |
| let cur_elem_ty = self.infer_expr_inner(expr, &expected); |
| coerce.coerce(self, Some(expr), &cur_elem_ty); |
| } |
| Some(items.len() as u64) |
| } |
| &Array::Repeat { initializer, repeat } => { |
| self.infer_expr_coerce(initializer, &Expectation::has_type(elem_ty)); |
| self.infer_expr( |
| repeat, |
| &Expectation::has_type( |
| TyKind::Scalar(Scalar::Uint(UintTy::Usize)).intern(&Interner), |
| ), |
| ); |
| |
| let repeat_expr = &self.body.exprs[repeat]; |
| consteval::eval_usize(repeat_expr) |
| } |
| }; |
| |
| TyKind::Array(coerce.complete(), consteval::usize_const(len)).intern(&Interner) |
| } |
| Expr::Literal(lit) => match lit { |
| Literal::Bool(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner), |
| Literal::String(..) => { |
| TyKind::Ref(Mutability::Not, static_lifetime(), TyKind::Str.intern(&Interner)) |
| .intern(&Interner) |
| } |
| Literal::ByteString(bs) => { |
| let byte_type = TyKind::Scalar(Scalar::Uint(UintTy::U8)).intern(&Interner); |
| |
| let len = consteval::usize_const(Some(bs.len() as u64)); |
| |
| let array_type = TyKind::Array(byte_type, len).intern(&Interner); |
| TyKind::Ref(Mutability::Not, static_lifetime(), array_type).intern(&Interner) |
| } |
| Literal::Char(..) => TyKind::Scalar(Scalar::Char).intern(&Interner), |
| Literal::Int(_v, ty) => match ty { |
| Some(int_ty) => { |
| TyKind::Scalar(Scalar::Int(primitive::int_ty_from_builtin(*int_ty))) |
| .intern(&Interner) |
| } |
| None => self.table.new_integer_var(), |
| }, |
| Literal::Uint(_v, ty) => match ty { |
| Some(int_ty) => { |
| TyKind::Scalar(Scalar::Uint(primitive::uint_ty_from_builtin(*int_ty))) |
| .intern(&Interner) |
| } |
| None => self.table.new_integer_var(), |
| }, |
| Literal::Float(_v, ty) => match ty { |
| Some(float_ty) => { |
| TyKind::Scalar(Scalar::Float(primitive::float_ty_from_builtin(*float_ty))) |
| .intern(&Interner) |
| } |
| None => self.table.new_float_var(), |
| }, |
| }, |
| Expr::MacroStmts { tail } => self.infer_expr_inner(*tail, expected), |
| }; |
| // use a new type variable if we got unknown here |
| let ty = self.insert_type_vars_shallow(ty); |
| self.write_expr_ty(tgt_expr, ty.clone()); |
| ty |
| } |
| |
| fn infer_overloadable_binop( |
| &mut self, |
| lhs: ExprId, |
| op: BinaryOp, |
| rhs: ExprId, |
| tgt_expr: ExprId, |
| ) -> Ty { |
| let lhs_expectation = Expectation::none(); |
| let lhs_ty = self.infer_expr(lhs, &lhs_expectation); |
| let rhs_ty = self.table.new_type_var(); |
| |
| let func = self.resolve_binop_method(op); |
| let func = match func { |
| Some(func) => func, |
| None => { |
| let rhs_ty = self.builtin_binary_op_rhs_expectation(op, lhs_ty.clone()); |
| let rhs_ty = self.infer_expr_coerce(rhs, &Expectation::from_option(rhs_ty)); |
| return self |
| .builtin_binary_op_return_ty(op, lhs_ty, rhs_ty) |
| .unwrap_or_else(|| self.err_ty()); |
| } |
| }; |
| |
| let subst = TyBuilder::subst_for_def(self.db, func) |
| .push(lhs_ty.clone()) |
| .push(rhs_ty.clone()) |
| .build(); |
| self.write_method_resolution(tgt_expr, func, subst.clone()); |
| |
| let method_ty = self.db.value_ty(func.into()).substitute(&Interner, &subst); |
| self.register_obligations_for_call(&method_ty); |
| |
| self.infer_expr_coerce(rhs, &Expectation::has_type(rhs_ty.clone())); |
| |
| let ret_ty = match method_ty.callable_sig(self.db) { |
| Some(sig) => sig.ret().clone(), |
| None => self.err_ty(), |
| }; |
| |
| let ret_ty = self.normalize_associated_types_in(ret_ty); |
| |
| // FIXME: record autoref adjustments |
| |
| // use knowledge of built-in binary ops, which can sometimes help inference |
| if let Some(builtin_rhs) = self.builtin_binary_op_rhs_expectation(op, lhs_ty.clone()) { |
| self.unify(&builtin_rhs, &rhs_ty); |
| } |
| if let Some(builtin_ret) = |
| self.builtin_binary_op_return_ty(op, lhs_ty.clone(), rhs_ty.clone()) |
| { |
| self.unify(&builtin_ret, &ret_ty); |
| } |
| |
| ret_ty |
| } |
| |
| fn infer_block( |
| &mut self, |
| expr: ExprId, |
| statements: &[Statement], |
| tail: Option<ExprId>, |
| expected: &Expectation, |
| ) -> Ty { |
| for stmt in statements { |
| match stmt { |
| Statement::Let { pat, type_ref, initializer } => { |
| let decl_ty = type_ref |
| .as_ref() |
| .map(|tr| self.make_ty(tr)) |
| .unwrap_or_else(|| self.err_ty()); |
| |
| // Always use the declared type when specified |
| let mut ty = decl_ty.clone(); |
| |
| if let Some(expr) = initializer { |
| let actual_ty = |
| self.infer_expr_coerce(*expr, &Expectation::has_type(decl_ty.clone())); |
| if decl_ty.is_unknown() { |
| ty = actual_ty; |
| } |
| } |
| |
| self.infer_pat(*pat, &ty, BindingMode::default()); |
| } |
| Statement::Expr { expr, .. } => { |
| self.infer_expr(*expr, &Expectation::none()); |
| } |
| } |
| } |
| |
| let ty = if let Some(expr) = tail { |
| self.infer_expr_coerce(expr, expected) |
| } else { |
| // Citing rustc: if there is no explicit tail expression, |
| // that is typically equivalent to a tail expression |
| // of `()` -- except if the block diverges. In that |
| // case, there is no value supplied from the tail |
| // expression (assuming there are no other breaks, |
| // this implies that the type of the block will be |
| // `!`). |
| if self.diverges.is_always() { |
| // we don't even make an attempt at coercion |
| self.table.new_maybe_never_var() |
| } else { |
| if let Some(t) = expected.only_has_type(&mut self.table) { |
| let _ = self.coerce(Some(expr), &TyBuilder::unit(), &t); |
| } |
| TyBuilder::unit() |
| } |
| }; |
| ty |
| } |
| |
| fn infer_method_call( |
| &mut self, |
| tgt_expr: ExprId, |
| receiver: ExprId, |
| args: &[ExprId], |
| method_name: &Name, |
| generic_args: Option<&GenericArgs>, |
| expected: &Expectation, |
| ) -> Ty { |
| let receiver_ty = self.infer_expr(receiver, &Expectation::none()); |
| let canonicalized_receiver = self.canonicalize(receiver_ty.clone()); |
| |
| let traits_in_scope = self.resolver.traits_in_scope(self.db.upcast()); |
| |
| let resolved = self.resolver.krate().and_then(|krate| { |
| method_resolution::lookup_method( |
| &canonicalized_receiver.value, |
| self.db, |
| self.trait_env.clone(), |
| krate, |
| &traits_in_scope, |
| self.resolver.module(), |
| method_name, |
| ) |
| }); |
| let (receiver_ty, method_ty, substs) = match resolved { |
| Some((ty, func)) => { |
| let ty = canonicalized_receiver.decanonicalize_ty(ty); |
| let generics = generics(self.db.upcast(), func.into()); |
| let substs = self.substs_for_method_call(generics, generic_args, &ty); |
| self.write_method_resolution(tgt_expr, func, substs.clone()); |
| (ty, self.db.value_ty(func.into()), substs) |
| } |
| None => ( |
| receiver_ty, |
| Binders::empty(&Interner, self.err_ty()), |
| Substitution::empty(&Interner), |
| ), |
| }; |
| let method_ty = method_ty.substitute(&Interner, &substs); |
| self.register_obligations_for_call(&method_ty); |
| let (formal_receiver_ty, param_tys, ret_ty) = match method_ty.callable_sig(self.db) { |
| Some(sig) => { |
| if !sig.params().is_empty() { |
| (sig.params()[0].clone(), sig.params()[1..].to_vec(), sig.ret().clone()) |
| } else { |
| (self.err_ty(), Vec::new(), sig.ret().clone()) |
| } |
| } |
| None => (self.err_ty(), Vec::new(), self.err_ty()), |
| }; |
| self.unify(&formal_receiver_ty, &receiver_ty); |
| |
| let expected_inputs = |
| self.expected_inputs_for_expected_output(expected, ret_ty.clone(), param_tys.clone()); |
| |
| self.check_call_arguments(args, &expected_inputs, ¶m_tys); |
| self.normalize_associated_types_in(ret_ty) |
| } |
| |
| fn expected_inputs_for_expected_output( |
| &mut self, |
| expected_output: &Expectation, |
| output: Ty, |
| inputs: Vec<Ty>, |
| ) -> Vec<Ty> { |
| if let Some(expected_ty) = expected_output.to_option(&mut self.table) { |
| let result = self.table.fudge_inference(|table| { |
| if table.try_unify(&expected_ty, &output).is_ok() { |
| table.resolve_with_fallback(inputs, |var, kind, _, _| match kind { |
| chalk_ir::VariableKind::Ty(tk) => var.to_ty(&Interner, tk).cast(&Interner), |
| chalk_ir::VariableKind::Lifetime => { |
| var.to_lifetime(&Interner).cast(&Interner) |
| } |
| chalk_ir::VariableKind::Const(ty) => { |
| var.to_const(&Interner, ty).cast(&Interner) |
| } |
| }) |
| } else { |
| Vec::new() |
| } |
| }); |
| result |
| } else { |
| Vec::new() |
| } |
| } |
| |
| fn check_call_arguments(&mut self, args: &[ExprId], expected_inputs: &[Ty], param_tys: &[Ty]) { |
| // Quoting https://github.com/rust-lang/rust/blob/6ef275e6c3cb1384ec78128eceeb4963ff788dca/src/librustc_typeck/check/mod.rs#L3325 -- |
| // We do this in a pretty awful way: first we type-check any arguments |
| // that are not closures, then we type-check the closures. This is so |
| // that we have more information about the types of arguments when we |
| // type-check the functions. This isn't really the right way to do this. |
| for &check_closures in &[false, true] { |
| let param_iter = param_tys.iter().cloned().chain(repeat(self.err_ty())); |
| let expected_iter = expected_inputs |
| .iter() |
| .cloned() |
| .chain(param_iter.clone().skip(expected_inputs.len())); |
| for ((&arg, param_ty), expected_ty) in args.iter().zip(param_iter).zip(expected_iter) { |
| let is_closure = matches!(&self.body[arg], Expr::Lambda { .. }); |
| if is_closure != check_closures { |
| continue; |
| } |
| |
| // the difference between param_ty and expected here is that |
| // expected is the parameter when the expected *return* type is |
| // taken into account. So in `let _: &[i32] = identity(&[1, 2])` |
| // the expected type is already `&[i32]`, whereas param_ty is |
| // still an unbound type variable. We don't always want to force |
| // the parameter to coerce to the expected type (for example in |
| // `coerce_unsize_expected_type_4`). |
| let param_ty = self.normalize_associated_types_in(param_ty); |
| let expected = Expectation::rvalue_hint(&mut self.table, expected_ty); |
| // infer with the expected type we have... |
| let ty = self.infer_expr_inner(arg, &expected); |
| |
| // then coerce to either the expected type or just the formal parameter type |
| let coercion_target = if let Some(ty) = expected.only_has_type(&mut self.table) { |
| // if we are coercing to the expectation, unify with the |
| // formal parameter type to connect everything |
| self.unify(&ty, ¶m_ty); |
| ty |
| } else { |
| param_ty |
| }; |
| if !coercion_target.is_unknown() { |
| if self.coerce(Some(arg), &ty, &coercion_target).is_err() { |
| self.result.type_mismatches.insert( |
| arg.into(), |
| TypeMismatch { expected: coercion_target, actual: ty.clone() }, |
| ); |
| } |
| } |
| } |
| } |
| } |
| |
| fn substs_for_method_call( |
| &mut self, |
| def_generics: Generics, |
| generic_args: Option<&GenericArgs>, |
| receiver_ty: &Ty, |
| ) -> Substitution { |
| let (parent_params, self_params, type_params, impl_trait_params) = |
| def_generics.provenance_split(); |
| assert_eq!(self_params, 0); // method shouldn't have another Self param |
| let total_len = parent_params + type_params + impl_trait_params; |
| let mut substs = Vec::with_capacity(total_len); |
| // Parent arguments are unknown, except for the receiver type |
| for (_id, param) in def_generics.iter_parent() { |
| if param.provenance == hir_def::generics::TypeParamProvenance::TraitSelf { |
| substs.push(receiver_ty.clone()); |
| } else { |
| substs.push(self.table.new_type_var()); |
| } |
| } |
| // handle provided type arguments |
| if let Some(generic_args) = generic_args { |
| // if args are provided, it should be all of them, but we can't rely on that |
| for arg in generic_args |
| .args |
| .iter() |
| .filter(|arg| matches!(arg, GenericArg::Type(_))) |
| .take(type_params) |
| { |
| match arg { |
| GenericArg::Type(type_ref) => { |
| let ty = self.make_ty(type_ref); |
| substs.push(ty); |
| } |
| GenericArg::Lifetime(_) => {} |
| } |
| } |
| }; |
| let supplied_params = substs.len(); |
| for _ in supplied_params..total_len { |
| substs.push(self.table.new_type_var()); |
| } |
| assert_eq!(substs.len(), total_len); |
| Substitution::from_iter(&Interner, substs) |
| } |
| |
| fn register_obligations_for_call(&mut self, callable_ty: &Ty) { |
| let callable_ty = self.resolve_ty_shallow(callable_ty); |
| if let TyKind::FnDef(fn_def, parameters) = callable_ty.kind(&Interner) { |
| let def: CallableDefId = from_chalk(self.db, *fn_def); |
| let generic_predicates = self.db.generic_predicates(def.into()); |
| for predicate in generic_predicates.iter() { |
| let (predicate, binders) = predicate |
| .clone() |
| .substitute(&Interner, parameters) |
| .into_value_and_skipped_binders(); |
| always!(binders.len(&Interner) == 0); // quantified where clauses not yet handled |
| self.push_obligation(predicate.cast(&Interner)); |
| } |
| // add obligation for trait implementation, if this is a trait method |
| match def { |
| CallableDefId::FunctionId(f) => { |
| if let AssocContainerId::TraitId(trait_) = f.lookup(self.db.upcast()).container |
| { |
| // construct a TraitRef |
| let substs = crate::subst_prefix( |
| &*parameters, |
| generics(self.db.upcast(), trait_.into()).len(), |
| ); |
| self.push_obligation( |
| TraitRef { trait_id: to_chalk_trait_id(trait_), substitution: substs } |
| .cast(&Interner), |
| ); |
| } |
| } |
| CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {} |
| } |
| } |
| } |
| |
| fn builtin_binary_op_return_ty(&mut self, op: BinaryOp, lhs_ty: Ty, rhs_ty: Ty) -> Option<Ty> { |
| let lhs_ty = self.resolve_ty_shallow(&lhs_ty); |
| let rhs_ty = self.resolve_ty_shallow(&rhs_ty); |
| match op { |
| BinaryOp::LogicOp(_) | BinaryOp::CmpOp(_) => { |
| Some(TyKind::Scalar(Scalar::Bool).intern(&Interner)) |
| } |
| BinaryOp::Assignment { .. } => Some(TyBuilder::unit()), |
| BinaryOp::ArithOp(ArithOp::Shl | ArithOp::Shr) => { |
| // all integer combinations are valid here |
| if matches!( |
| lhs_ty.kind(&Interner), |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)) |
| | TyKind::InferenceVar(_, TyVariableKind::Integer) |
| ) && matches!( |
| rhs_ty.kind(&Interner), |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)) |
| | TyKind::InferenceVar(_, TyVariableKind::Integer) |
| ) { |
| Some(lhs_ty) |
| } else { |
| None |
| } |
| } |
| BinaryOp::ArithOp(_) => match (lhs_ty.kind(&Interner), rhs_ty.kind(&Interner)) { |
| // (int, int) | (uint, uint) | (float, float) |
| (TyKind::Scalar(Scalar::Int(_)), TyKind::Scalar(Scalar::Int(_))) |
| | (TyKind::Scalar(Scalar::Uint(_)), TyKind::Scalar(Scalar::Uint(_))) |
| | (TyKind::Scalar(Scalar::Float(_)), TyKind::Scalar(Scalar::Float(_))) => { |
| Some(rhs_ty) |
| } |
| // ({int}, int) | ({int}, uint) |
| ( |
| TyKind::InferenceVar(_, TyVariableKind::Integer), |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)), |
| ) => Some(rhs_ty), |
| // (int, {int}) | (uint, {int}) |
| ( |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_)), |
| TyKind::InferenceVar(_, TyVariableKind::Integer), |
| ) => Some(lhs_ty), |
| // ({float} | float) |
| ( |
| TyKind::InferenceVar(_, TyVariableKind::Float), |
| TyKind::Scalar(Scalar::Float(_)), |
| ) => Some(rhs_ty), |
| // (float, {float}) |
| ( |
| TyKind::Scalar(Scalar::Float(_)), |
| TyKind::InferenceVar(_, TyVariableKind::Float), |
| ) => Some(lhs_ty), |
| // ({int}, {int}) | ({float}, {float}) |
| ( |
| TyKind::InferenceVar(_, TyVariableKind::Integer), |
| TyKind::InferenceVar(_, TyVariableKind::Integer), |
| ) |
| | ( |
| TyKind::InferenceVar(_, TyVariableKind::Float), |
| TyKind::InferenceVar(_, TyVariableKind::Float), |
| ) => Some(rhs_ty), |
| _ => None, |
| }, |
| } |
| } |
| |
| fn builtin_binary_op_rhs_expectation(&mut self, op: BinaryOp, lhs_ty: Ty) -> Option<Ty> { |
| Some(match op { |
| BinaryOp::LogicOp(..) => TyKind::Scalar(Scalar::Bool).intern(&Interner), |
| BinaryOp::Assignment { op: None } => lhs_ty, |
| BinaryOp::CmpOp(CmpOp::Eq { .. }) => match self |
| .resolve_ty_shallow(&lhs_ty) |
| .kind(&Interner) |
| { |
| TyKind::Scalar(_) | TyKind::Str => lhs_ty, |
| TyKind::InferenceVar(_, TyVariableKind::Integer | TyVariableKind::Float) => lhs_ty, |
| _ => return None, |
| }, |
| BinaryOp::ArithOp(ArithOp::Shl | ArithOp::Shr) => return None, |
| BinaryOp::CmpOp(CmpOp::Ord { .. }) |
| | BinaryOp::Assignment { op: Some(_) } |
| | BinaryOp::ArithOp(_) => match self.resolve_ty_shallow(&lhs_ty).kind(&Interner) { |
| TyKind::Scalar(Scalar::Int(_) | Scalar::Uint(_) | Scalar::Float(_)) => lhs_ty, |
| TyKind::InferenceVar(_, TyVariableKind::Integer | TyVariableKind::Float) => lhs_ty, |
| _ => return None, |
| }, |
| }) |
| } |
| |
| fn resolve_binop_method(&self, op: BinaryOp) -> Option<FunctionId> { |
| let (name, lang_item) = match op { |
| BinaryOp::LogicOp(_) => return None, |
| BinaryOp::ArithOp(aop) => match aop { |
| ArithOp::Add => (name!(add), "add"), |
| ArithOp::Mul => (name!(mul), "mul"), |
| ArithOp::Sub => (name!(sub), "sub"), |
| ArithOp::Div => (name!(div), "div"), |
| ArithOp::Rem => (name!(rem), "rem"), |
| ArithOp::Shl => (name!(shl), "shl"), |
| ArithOp::Shr => (name!(shr), "shr"), |
| ArithOp::BitXor => (name!(bitxor), "bitxor"), |
| ArithOp::BitOr => (name!(bitor), "bitor"), |
| ArithOp::BitAnd => (name!(bitand), "bitand"), |
| }, |
| BinaryOp::Assignment { op: Some(aop) } => match aop { |
| ArithOp::Add => (name!(add_assign), "add_assign"), |
| ArithOp::Mul => (name!(mul_assign), "mul_assign"), |
| ArithOp::Sub => (name!(sub_assign), "sub_assign"), |
| ArithOp::Div => (name!(div_assign), "div_assign"), |
| ArithOp::Rem => (name!(rem_assign), "rem_assign"), |
| ArithOp::Shl => (name!(shl_assign), "shl_assign"), |
| ArithOp::Shr => (name!(shr_assign), "shr_assign"), |
| ArithOp::BitXor => (name!(bitxor_assign), "bitxor_assign"), |
| ArithOp::BitOr => (name!(bitor_assign), "bitor_assign"), |
| ArithOp::BitAnd => (name!(bitand_assign), "bitand_assign"), |
| }, |
| BinaryOp::CmpOp(cop) => match cop { |
| CmpOp::Eq { negated: false } => (name!(eq), "eq"), |
| CmpOp::Eq { negated: true } => (name!(ne), "eq"), |
| CmpOp::Ord { ordering: Ordering::Less, strict: false } => { |
| (name!(le), "partial_ord") |
| } |
| CmpOp::Ord { ordering: Ordering::Less, strict: true } => (name!(lt), "partial_ord"), |
| CmpOp::Ord { ordering: Ordering::Greater, strict: false } => { |
| (name!(ge), "partial_ord") |
| } |
| CmpOp::Ord { ordering: Ordering::Greater, strict: true } => { |
| (name!(gt), "partial_ord") |
| } |
| }, |
| BinaryOp::Assignment { op: None } => return None, |
| }; |
| |
| let trait_ = self.resolve_lang_item(lang_item)?.as_trait()?; |
| |
| self.db.trait_data(trait_).method_by_name(&name) |
| } |
| } |
