From 6a77ec7bbe6ddbf663dce9529d11d1bb56c5489a Mon Sep 17 00:00:00 2001 From: Aleksey Kladov Date: Thu, 13 Aug 2020 16:35:29 +0200 Subject: Rename ra_hir_ty -> hir_ty --- crates/ra_hir_ty/src/infer/expr.rs | 873 ------------------------------------- 1 file changed, 873 deletions(-) delete mode 100644 crates/ra_hir_ty/src/infer/expr.rs (limited to 'crates/ra_hir_ty/src/infer/expr.rs') diff --git a/crates/ra_hir_ty/src/infer/expr.rs b/crates/ra_hir_ty/src/infer/expr.rs deleted file mode 100644 index a2f849d02..000000000 --- a/crates/ra_hir_ty/src/infer/expr.rs +++ /dev/null @@ -1,873 +0,0 @@ -//! Type inference for expressions. - -use std::iter::{repeat, repeat_with}; -use std::{mem, sync::Arc}; - -use hir_def::{ - builtin_type::Signedness, - expr::{Array, BinaryOp, Expr, ExprId, Literal, Statement, UnaryOp}, - path::{GenericArg, GenericArgs}, - resolver::resolver_for_expr, - AdtId, AssocContainerId, FieldId, Lookup, -}; -use hir_expand::name::{name, Name}; -use syntax::ast::RangeOp; - -use crate::{ - autoderef, method_resolution, op, - traits::{FnTrait, InEnvironment}, - utils::{generics, variant_data, Generics}, - ApplicationTy, Binders, CallableDefId, InferTy, IntTy, Mutability, Obligation, Rawness, Substs, - TraitRef, Ty, TypeCtor, -}; - -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 ty.is_never() { - // Any expression that produces a value of type `!` must have diverged - self.diverges = Diverges::Always; - } - let could_unify = self.unify(&ty, &expected.ty); - if !could_unify { - self.result.type_mismatches.insert( - tgt_expr, - TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() }, - ); - } - self.resolve_ty_as_possible(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 !self.coerce(&ty, &expected.coercion_target()) { - self.result - .type_mismatches - .insert(expr, TypeMismatch { expected: expected.ty.clone(), actual: ty.clone() }); - // Return actual type when type mismatch. - // This is needed for diagnostic when return type mismatch. - ty - } else if expected.coercion_target() == &Ty::Unknown { - ty - } else { - expected.ty.clone() - }; - - self.resolve_ty_as_possible(ty) - } - - fn callable_sig_from_fn_trait(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec, 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 generic_params = generics(self.db.upcast(), fn_once_trait.into()); - if generic_params.len() != 2 { - return None; - } - - let mut param_builder = Substs::builder(num_args); - let mut arg_tys = vec![]; - for _ in 0..num_args { - let arg = self.table.new_type_var(); - param_builder = param_builder.push(arg.clone()); - arg_tys.push(arg); - } - let parameters = param_builder.build(); - let arg_ty = Ty::Apply(ApplicationTy { - ctor: TypeCtor::Tuple { cardinality: num_args as u16 }, - parameters, - }); - let substs = - Substs::build_for_generics(&generic_params).push(ty.clone()).push(arg_ty).build(); - - let trait_env = Arc::clone(&self.trait_env); - let implements_fn_trait = - Obligation::Trait(TraitRef { trait_: fn_once_trait, substs: substs.clone() }); - let goal = self.canonicalizer().canonicalize_obligation(InEnvironment { - value: implements_fn_trait.clone(), - environment: trait_env, - }); - if self.db.trait_solve(krate, goal.value).is_some() { - self.obligations.push(implements_fn_trait); - let output_proj_ty = - crate::ProjectionTy { associated_ty: output_assoc_type, parameters: substs }; - let return_ty = self.normalize_projection_ty(output_proj_ty); - Some((arg_tys, return_ty)) - } else { - None - } - } - - pub fn callable_sig(&mut self, ty: &Ty, num_args: usize) -> Option<(Vec, 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 { - let body = Arc::clone(&self.body); // avoid borrow checker problem - let ty = match &body[tgt_expr] { - Expr::Missing => Ty::Unknown, - 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(Ty::simple(TypeCtor::Bool))); - - let condition_diverges = mem::replace(&mut self.diverges, Diverges::Maybe); - let mut both_arms_diverge = Diverges::Always; - - let then_ty = self.infer_expr_inner(*then_branch, &expected); - both_arms_diverge &= mem::replace(&mut self.diverges, Diverges::Maybe); - let else_ty = match else_branch { - Some(else_branch) => self.infer_expr_inner(*else_branch, &expected), - None => Ty::unit(), - }; - both_arms_diverge &= self.diverges; - - self.diverges = condition_diverges | both_arms_diverge; - - self.coerce_merge_branch(&then_ty, &else_ty) - } - Expr::Block { statements, tail, .. } => { - // FIXME: Breakable block inference - self.infer_block(statements, *tail, expected) - } - Expr::Unsafe { body } => self.infer_expr(*body, expected), - Expr::TryBlock { body } => { - let _inner = self.infer_expr(*body, expected); - // FIXME should be std::result::Result<{inner}, _> - Ty::Unknown - } - Expr::Loop { body, label } => { - self.breakables.push(BreakableContext { - may_break: false, - break_ty: self.table.new_type_var(), - label: label.clone(), - }); - self.infer_expr(*body, &Expectation::has_type(Ty::unit())); - - let ctxt = self.breakables.pop().expect("breakable stack broken"); - if ctxt.may_break { - self.diverges = Diverges::Maybe; - } - - if ctxt.may_break { - ctxt.break_ty - } else { - Ty::simple(TypeCtor::Never) - } - } - Expr::While { condition, body, label } => { - self.breakables.push(BreakableContext { - may_break: false, - break_ty: Ty::Unknown, - label: label.clone(), - }); - // while let is desugared to a match loop, so this is always simple while - self.infer_expr(*condition, &Expectation::has_type(Ty::simple(TypeCtor::Bool))); - self.infer_expr(*body, &Expectation::has_type(Ty::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; - Ty::unit() - } - Expr::For { iterable, body, pat, label } => { - let iterable_ty = self.infer_expr(*iterable, &Expectation::none()); - - self.breakables.push(BreakableContext { - may_break: false, - break_ty: Ty::Unknown, - label: label.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(Ty::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; - Ty::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 = Ty::apply( - TypeCtor::FnPtr { num_args: sig_tys.len() as u16 - 1, is_varargs: false }, - Substs(sig_tys.clone().into()), - ); - let closure_ty = - Ty::apply_one(TypeCtor::Closure { def: self.owner, expr: tgt_expr }, sig_ty); - - // Eagerly try to relate the closure type with the expected - // type, otherwise we often won't have enough information to - // infer the body. - self.coerce(&closure_ty, &expected.ty); - - // Now go through the argument patterns - for (arg_pat, arg_ty) in args.iter().zip(sig_tys) { - let resolved = self.resolve_ty_as_possible(arg_ty); - self.infer_pat(*arg_pat, &resolved, 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.canonicalizer().canonicalize_ty(callee_ty.clone()); - let mut derefs = autoderef( - self.db, - self.resolver.krate(), - InEnvironment { - value: canonicalized.value.clone(), - environment: self.trait_env.clone(), - }, - ); - let (param_tys, ret_ty): (Vec, Ty) = derefs - .find_map(|callee_deref_ty| { - self.callable_sig( - &canonicalized.decanonicalize_ty(callee_deref_ty.value), - args.len(), - ) - }) - .unwrap_or((Vec::new(), Ty::Unknown)); - self.register_obligations_for_call(&callee_ty); - self.check_call_arguments(args, ¶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_ref()), - Expr::Match { expr, arms } => { - let input_ty = self.infer_expr(*expr, &Expectation::none()); - - let mut result_ty = if arms.is_empty() { - Ty::simple(TypeCtor::Never) - } else { - self.table.new_type_var() - }; - - 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()); - if let Some(guard_expr) = arm.guard { - self.infer_expr( - guard_expr, - &Expectation::has_type(Ty::simple(TypeCtor::Bool)), - ); - } - - let arm_ty = self.infer_expr_inner(arm.expr, &expected); - all_arms_diverge &= self.diverges; - result_ty = self.coerce_merge_branch(&result_ty, &arm_ty); - } - - self.diverges = matchee_diverges | all_arms_diverge; - - result_ty - } - 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(Ty::Unknown) - } - Expr::Continue { .. } => Ty::simple(TypeCtor::Never), - Expr::Break { expr, label } => { - let val_ty = if let Some(expr) = expr { - self.infer_expr(*expr, &Expectation::none()) - } else { - Ty::unit() - }; - - let last_ty = - if let Some(ctxt) = find_breakable(&mut self.breakables, label.as_ref()) { - ctxt.break_ty.clone() - } else { - Ty::Unknown - }; - - let merged_type = self.coerce_merge_branch(&last_ty, &val_ty); - - if let Some(ctxt) = find_breakable(&mut self.breakables, label.as_ref()) { - ctxt.break_ty = merged_type; - ctxt.may_break = true; - } else { - self.push_diagnostic(InferenceDiagnostic::BreakOutsideOfLoop { - expr: tgt_expr, - }); - } - - Ty::simple(TypeCtor::Never) - } - Expr::Return { expr } => { - if let Some(expr) = expr { - self.infer_expr_coerce(*expr, &Expectation::has_type(self.return_ty.clone())); - } else { - let unit = Ty::unit(); - self.coerce(&unit, &self.return_ty.clone()); - } - Ty::simple(TypeCtor::Never) - } - Expr::RecordLit { path, fields, spread } => { - let (ty, def_id) = self.resolve_variant(path.as_ref()); - if let Some(variant) = def_id { - self.write_variant_resolution(tgt_expr.into(), variant); - } - - self.unify(&ty, &expected.ty); - - let substs = ty.substs().unwrap_or_else(Substs::empty); - let field_types = def_id.map(|it| self.db.field_types(it)).unwrap_or_default(); - let variant_data = def_id.map(|it| variant_data(self.db.upcast(), it)); - for (field_idx, field) in fields.iter().enumerate() { - 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: tgt_expr, - field: field_idx, - }); - None - } - }); - if let Some(field_def) = field_def { - self.result.record_field_resolutions.insert(field.expr, field_def); - } - let field_ty = field_def - .map_or(Ty::Unknown, |it| field_types[it.local_id].clone().subst(&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.canonicalizer().canonicalize_ty(receiver_ty); - let ty = autoderef::autoderef( - self.db, - self.resolver.krate(), - InEnvironment { - value: canonicalized.value.clone(), - environment: self.trait_env.clone(), - }, - ) - .find_map(|derefed_ty| match canonicalized.decanonicalize_ty(derefed_ty.value) { - Ty::Apply(a_ty) => match a_ty.ctor { - TypeCtor::Tuple { .. } => name - .as_tuple_index() - .and_then(|idx| a_ty.parameters.0.get(idx).cloned()), - TypeCtor::Adt(AdtId::StructId(s)) => { - self.db.struct_data(s).variant_data.field(name).map(|local_id| { - let field = FieldId { parent: s.into(), local_id }; - self.write_field_resolution(tgt_expr, field); - self.db.field_types(s.into())[field.local_id] - .clone() - .subst(&a_ty.parameters) - }) - } - TypeCtor::Adt(AdtId::UnionId(u)) => { - self.db.union_data(u).variant_data.field(name).map(|local_id| { - let field = FieldId { parent: u.into(), local_id }; - self.write_field_resolution(tgt_expr, field); - self.db.field_types(u.into())[field.local_id] - .clone() - .subst(&a_ty.parameters) - }) - } - _ => None, - }, - _ => None, - }) - .unwrap_or(Ty::Unknown); - 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 } => { - 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 expectation = if let Some((exp_inner, exp_rawness, exp_mutability)) = - &expected.ty.as_reference_or_ptr() - { - if *exp_mutability == Mutability::Mut && *mutability == Mutability::Shared { - // FIXME: throw type error - expected mut reference but found shared ref, - // which cannot be coerced - } - if *exp_rawness == Rawness::Ref && *rawness == Rawness::RawPtr { - // FIXME: throw type error - expected reference but found ptr, - // which cannot be coerced - } - Expectation::rvalue_hint(Ty::clone(exp_inner)) - } else { - Expectation::none() - }; - let inner_ty = self.infer_expr_inner(*expr, &expectation); - let ty = match rawness { - Rawness::RawPtr => TypeCtor::RawPtr(*mutability), - Rawness::Ref => TypeCtor::Ref(*mutability), - }; - Ty::apply_one(ty, inner_ty) - } - Expr::Box { expr } => { - let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); - if let Some(box_) = self.resolve_boxed_box() { - Ty::apply_one(TypeCtor::Adt(box_), inner_ty) - } else { - Ty::Unknown - } - } - Expr::UnaryOp { expr, op } => { - let inner_ty = self.infer_expr_inner(*expr, &Expectation::none()); - match op { - UnaryOp::Deref => match self.resolver.krate() { - Some(krate) => { - let canonicalized = self.canonicalizer().canonicalize_ty(inner_ty); - match autoderef::deref( - self.db, - krate, - InEnvironment { - value: &canonicalized.value, - environment: self.trait_env.clone(), - }, - ) { - Some(derefed_ty) => { - canonicalized.decanonicalize_ty(derefed_ty.value) - } - None => Ty::Unknown, - } - } - None => Ty::Unknown, - }, - UnaryOp::Neg => { - match &inner_ty { - // Fast path for builtins - Ty::Apply(ApplicationTy { - ctor: TypeCtor::Int(IntTy { signedness: Signedness::Signed, .. }), - .. - }) - | Ty::Apply(ApplicationTy { ctor: TypeCtor::Float(_), .. }) - | Ty::Infer(InferTy::IntVar(..)) - | Ty::Infer(InferTy::FloatVar(..)) => 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 { - // Fast path for builtins - Ty::Apply(ApplicationTy { ctor: TypeCtor::Bool, .. }) - | Ty::Apply(ApplicationTy { ctor: TypeCtor::Int(_), .. }) - | Ty::Infer(InferTy::IntVar(..)) => 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(op) => { - let lhs_expectation = match op { - BinaryOp::LogicOp(..) => Expectation::has_type(Ty::simple(TypeCtor::Bool)), - _ => Expectation::none(), - }; - let lhs_ty = self.infer_expr(*lhs, &lhs_expectation); - // FIXME: find implementation of trait corresponding to operation - // symbol and resolve associated `Output` type - let rhs_expectation = op::binary_op_rhs_expectation(*op, lhs_ty.clone()); - let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation)); - - // FIXME: similar as above, return ty is often associated trait type - op::binary_op_return_ty(*op, lhs_ty, rhs_ty) - } - _ => Ty::Unknown, - }, - 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) => Ty::simple(TypeCtor::Adt(adt)), - None => Ty::Unknown, - }, - (RangeOp::Exclusive, None, Some(ty)) => match self.resolve_range_to() { - Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty), - None => Ty::Unknown, - }, - (RangeOp::Inclusive, None, Some(ty)) => { - match self.resolve_range_to_inclusive() { - Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty), - None => Ty::Unknown, - } - } - (RangeOp::Exclusive, Some(_), Some(ty)) => match self.resolve_range() { - Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty), - None => Ty::Unknown, - }, - (RangeOp::Inclusive, Some(_), Some(ty)) => { - match self.resolve_range_inclusive() { - Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty), - None => Ty::Unknown, - } - } - (RangeOp::Exclusive, Some(ty), None) => match self.resolve_range_from() { - Some(adt) => Ty::apply_one(TypeCtor::Adt(adt), ty), - None => Ty::Unknown, - }, - (RangeOp::Inclusive, _, None) => Ty::Unknown, - } - } - 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.canonicalizer().canonicalize_ty(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(Ty::Unknown, |t| canonicalized.decanonicalize_ty(t.value)); - self.resolve_associated_type_with_params( - self_ty, - self.resolve_ops_index_output(), - &[index_ty], - ) - } else { - Ty::Unknown - } - } - Expr::Tuple { exprs } => { - let mut tys = match &expected.ty { - ty_app!(TypeCtor::Tuple { .. }, st) => st - .iter() - .cloned() - .chain(repeat_with(|| self.table.new_type_var())) - .take(exprs.len()) - .collect::>(), - _ => (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())); - } - - Ty::apply(TypeCtor::Tuple { cardinality: tys.len() as u16 }, Substs(tys.into())) - } - Expr::Array(array) => { - let elem_ty = match &expected.ty { - ty_app!(TypeCtor::Array, st) | ty_app!(TypeCtor::Slice, st) => { - st.as_single().clone() - } - _ => self.table.new_type_var(), - }; - - match array { - Array::ElementList(items) => { - for expr in items.iter() { - self.infer_expr_coerce(*expr, &Expectation::has_type(elem_ty.clone())); - } - } - Array::Repeat { initializer, repeat } => { - self.infer_expr_coerce( - *initializer, - &Expectation::has_type(elem_ty.clone()), - ); - self.infer_expr( - *repeat, - &Expectation::has_type(Ty::simple(TypeCtor::Int(IntTy::usize()))), - ); - } - } - - Ty::apply_one(TypeCtor::Array, elem_ty) - } - Expr::Literal(lit) => match lit { - Literal::Bool(..) => Ty::simple(TypeCtor::Bool), - Literal::String(..) => { - Ty::apply_one(TypeCtor::Ref(Mutability::Shared), Ty::simple(TypeCtor::Str)) - } - Literal::ByteString(..) => { - let byte_type = Ty::simple(TypeCtor::Int(IntTy::u8())); - let array_type = Ty::apply_one(TypeCtor::Array, byte_type); - Ty::apply_one(TypeCtor::Ref(Mutability::Shared), array_type) - } - Literal::Char(..) => Ty::simple(TypeCtor::Char), - Literal::Int(_v, ty) => match ty { - Some(int_ty) => Ty::simple(TypeCtor::Int((*int_ty).into())), - None => self.table.new_integer_var(), - }, - Literal::Float(_v, ty) => match ty { - Some(float_ty) => Ty::simple(TypeCtor::Float((*float_ty).into())), - None => self.table.new_float_var(), - }, - }, - }; - // use a new type variable if we got Ty::Unknown here - let ty = self.insert_type_vars_shallow(ty); - let ty = self.resolve_ty_as_possible(ty); - self.write_expr_ty(tgt_expr, ty.clone()); - ty - } - - fn infer_block( - &mut self, - statements: &[Statement], - tail: Option, - 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(Ty::Unknown); - - // 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 == Ty::Unknown { - ty = actual_ty; - } - } - - let ty = self.resolve_ty_as_possible(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_type_var() - } else { - self.coerce(&Ty::unit(), expected.coercion_target()); - Ty::unit() - } - }; - ty - } - - fn infer_method_call( - &mut self, - tgt_expr: ExprId, - receiver: ExprId, - args: &[ExprId], - method_name: &Name, - generic_args: Option<&GenericArgs>, - ) -> Ty { - let receiver_ty = self.infer_expr(receiver, &Expectation::none()); - let canonicalized_receiver = self.canonicalizer().canonicalize_ty(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, - method_name, - ) - }); - let (derefed_receiver_ty, method_ty, def_generics) = match resolved { - Some((ty, func)) => { - let ty = canonicalized_receiver.decanonicalize_ty(ty); - self.write_method_resolution(tgt_expr, func); - (ty, self.db.value_ty(func.into()), Some(generics(self.db.upcast(), func.into()))) - } - None => (receiver_ty, Binders::new(0, Ty::Unknown), None), - }; - let substs = self.substs_for_method_call(def_generics, generic_args, &derefed_receiver_ty); - let method_ty = method_ty.subst(&substs); - let method_ty = self.insert_type_vars(method_ty); - self.register_obligations_for_call(&method_ty); - let (expected_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 { - (Ty::Unknown, Vec::new(), sig.ret().clone()) - } - } - None => (Ty::Unknown, Vec::new(), Ty::Unknown), - }; - // Apply autoref so the below unification works correctly - // FIXME: return correct autorefs from lookup_method - let actual_receiver_ty = match expected_receiver_ty.as_reference() { - Some((_, mutability)) => Ty::apply_one(TypeCtor::Ref(mutability), derefed_receiver_ty), - _ => derefed_receiver_ty, - }; - self.unify(&expected_receiver_ty, &actual_receiver_ty); - - self.check_call_arguments(args, ¶m_tys); - self.normalize_associated_types_in(ret_ty) - } - - fn check_call_arguments(&mut self, args: &[ExprId], 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(Ty::Unknown)); - for (&arg, param_ty) in args.iter().zip(param_iter) { - let is_closure = matches!(&self.body[arg], Expr::Lambda { .. }); - if is_closure != check_closures { - continue; - } - - let param_ty = self.normalize_associated_types_in(param_ty); - self.infer_expr_coerce(arg, &Expectation::has_type(param_ty.clone())); - } - } - } - - fn substs_for_method_call( - &mut self, - def_generics: Option, - generic_args: Option<&GenericArgs>, - receiver_ty: &Ty, - ) -> Substs { - let (parent_params, self_params, type_params, impl_trait_params) = - def_generics.as_ref().map_or((0, 0, 0, 0), |g| g.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 - if let Some(parent_generics) = def_generics.as_ref().map(|p| p.iter_parent()) { - for (_id, param) in parent_generics { - if param.provenance == hir_def::generics::TypeParamProvenance::TraitSelf { - substs.push(receiver_ty.clone()); - } else { - substs.push(Ty::Unknown); - } - } - } - // 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().take(type_params) { - match arg { - GenericArg::Type(type_ref) => { - let ty = self.make_ty(type_ref); - substs.push(ty); - } - } - } - }; - let supplied_params = substs.len(); - for _ in supplied_params..total_len { - substs.push(Ty::Unknown); - } - assert_eq!(substs.len(), total_len); - Substs(substs.into()) - } - - fn register_obligations_for_call(&mut self, callable_ty: &Ty) { - if let Ty::Apply(a_ty) = callable_ty { - if let TypeCtor::FnDef(def) = a_ty.ctor { - let generic_predicates = self.db.generic_predicates(def.into()); - for predicate in generic_predicates.iter() { - let predicate = predicate.clone().subst(&a_ty.parameters); - if let Some(obligation) = Obligation::from_predicate(predicate) { - self.obligations.push(obligation); - } - } - // 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 TraitDef - let substs = a_ty - .parameters - .prefix(generics(self.db.upcast(), trait_.into()).len()); - self.obligations.push(Obligation::Trait(TraitRef { trait_, substs })); - } - } - CallableDefId::StructId(_) | CallableDefId::EnumVariantId(_) => {} - } - } - } - } -} -- cgit v1.2.3