From e12bf9b412a47d1514ea921003a55fb9b77b2020 Mon Sep 17 00:00:00 2001 From: jfecher Date: Thu, 9 May 2024 12:57:58 -0500 Subject: [PATCH] chore(experimental): Add Elaborator pass (#4992) # Description ## Problem\* Resolves #4953 ## Summary\* Adds an elaborator - a concept borrowed from dependently typed languages - which performs name resolution and type checking simultaneously. The new elaborator is currently disabled (inaccessible from user code) since it is not hooked up to the `dc_crate` module. This PR is extremely large (sorry!) but is 99% a pseudo copy-paste of existing code from the name resolver and type checker, only slightly adapted to be able to work in tandem. Unfortunately, this also means that we'll need to duplicate any changes made to the name resolver & type checker in the elaborator as well until we can remove the old name resolution and type checking passes. For example, https://github.com/noir-lang/noir/pull/4958 will need to be integrated into the elaborator as well. ## Additional Context After this PR the plan is to 1. Connect the elaborator to `dc_crate`, enabling it with a command-line option. 2. Insert logic for the comptime scanning pass in the elaborator as well. 3. Test the elaborator against all existing tests. 4. Once it passes, we can use the elaborator by default and delete the name resolution, type checking, and comptime scanning passes. ## Documentation\* Check one: - [x] No documentation needed. - [ ] Documentation included in this PR. - [ ] **[For Experimental Features]** Documentation to be submitted in a separate PR. # PR Checklist\* - [x] I have tested the changes locally. - [ ] I have formatted the changes with [Prettier](https://prettier.io/) and/or `cargo fmt` on default settings. --- compiler/noirc_frontend/src/ast/statement.rs | 5 +- .../src/elaborator/expressions.rs | 604 +++++++ compiler/noirc_frontend/src/elaborator/mod.rs | 159 ++ .../noirc_frontend/src/elaborator/patterns.rs | 463 ++++++ .../noirc_frontend/src/elaborator/scope.rs | 100 ++ .../src/elaborator/statements.rs | 409 +++++ .../noirc_frontend/src/elaborator/types.rs | 1399 +++++++++++++++++ .../src/hir/resolution/import.rs | 9 + .../src/hir/resolution/resolver.rs | 12 +- .../noirc_frontend/src/hir/type_check/expr.rs | 4 +- .../noirc_frontend/src/hir/type_check/mod.rs | 2 +- compiler/noirc_frontend/src/hir_def/expr.rs | 11 +- compiler/noirc_frontend/src/hir_def/types.rs | 8 +- compiler/noirc_frontend/src/lib.rs | 1 + compiler/noirc_frontend/src/node_interner.rs | 6 +- 15 files changed, 3170 insertions(+), 22 deletions(-) create mode 100644 compiler/noirc_frontend/src/elaborator/expressions.rs create mode 100644 compiler/noirc_frontend/src/elaborator/mod.rs create mode 100644 compiler/noirc_frontend/src/elaborator/patterns.rs create mode 100644 compiler/noirc_frontend/src/elaborator/scope.rs create mode 100644 compiler/noirc_frontend/src/elaborator/statements.rs create mode 100644 compiler/noirc_frontend/src/elaborator/types.rs diff --git a/compiler/noirc_frontend/src/ast/statement.rs b/compiler/noirc_frontend/src/ast/statement.rs index 0da39edfd85..94b5841e52c 100644 --- a/compiler/noirc_frontend/src/ast/statement.rs +++ b/compiler/noirc_frontend/src/ast/statement.rs @@ -565,7 +565,7 @@ impl ForRange { identifier: Ident, block: Expression, for_loop_span: Span, - ) -> StatementKind { + ) -> Statement { /// Counter used to generate unique names when desugaring /// code in the parser requires the creation of fresh variables. /// The parser is stateless so this is a static global instead. @@ -662,7 +662,8 @@ impl ForRange { let block = ExpressionKind::Block(BlockExpression { statements: vec![let_array, for_loop], }); - StatementKind::Expression(Expression::new(block, for_loop_span)) + let kind = StatementKind::Expression(Expression::new(block, for_loop_span)); + Statement { kind, span: for_loop_span } } } } diff --git a/compiler/noirc_frontend/src/elaborator/expressions.rs b/compiler/noirc_frontend/src/elaborator/expressions.rs new file mode 100644 index 00000000000..19ee67b442c --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/expressions.rs @@ -0,0 +1,604 @@ +use iter_extended::vecmap; +use noirc_errors::{Location, Span}; +use regex::Regex; +use rustc_hash::FxHashSet as HashSet; + +use crate::{ + ast::{ + ArrayLiteral, ConstructorExpression, IfExpression, InfixExpression, Lambda, + UnresolvedTypeExpression, + }, + hir::{ + resolution::{errors::ResolverError, resolver::LambdaContext}, + type_check::TypeCheckError, + }, + hir_def::{ + expr::{ + HirArrayLiteral, HirBinaryOp, HirBlockExpression, HirCallExpression, HirCastExpression, + HirConstructorExpression, HirIdent, HirIfExpression, HirIndexExpression, + HirInfixExpression, HirLambda, HirMemberAccess, HirMethodCallExpression, + HirMethodReference, HirPrefixExpression, + }, + traits::TraitConstraint, + }, + macros_api::{ + BlockExpression, CallExpression, CastExpression, Expression, ExpressionKind, HirExpression, + HirLiteral, HirStatement, Ident, IndexExpression, Literal, MemberAccessExpression, + MethodCallExpression, PrefixExpression, + }, + node_interner::{DefinitionKind, ExprId, FuncId}, + Shared, StructType, Type, +}; + +use super::Elaborator; + +impl Elaborator { + pub(super) fn elaborate_expression(&mut self, expr: Expression) -> (ExprId, Type) { + let (hir_expr, typ) = match expr.kind { + ExpressionKind::Literal(literal) => self.elaborate_literal(literal, expr.span), + ExpressionKind::Block(block) => self.elaborate_block(block), + ExpressionKind::Prefix(prefix) => self.elaborate_prefix(*prefix), + ExpressionKind::Index(index) => self.elaborate_index(*index), + ExpressionKind::Call(call) => self.elaborate_call(*call, expr.span), + ExpressionKind::MethodCall(call) => self.elaborate_method_call(*call, expr.span), + ExpressionKind::Constructor(constructor) => self.elaborate_constructor(*constructor), + ExpressionKind::MemberAccess(access) => { + return self.elaborate_member_access(*access, expr.span) + } + ExpressionKind::Cast(cast) => self.elaborate_cast(*cast, expr.span), + ExpressionKind::Infix(infix) => return self.elaborate_infix(*infix, expr.span), + ExpressionKind::If(if_) => self.elaborate_if(*if_), + ExpressionKind::Variable(variable) => return self.elaborate_variable(variable), + ExpressionKind::Tuple(tuple) => self.elaborate_tuple(tuple), + ExpressionKind::Lambda(lambda) => self.elaborate_lambda(*lambda), + ExpressionKind::Parenthesized(expr) => return self.elaborate_expression(*expr), + ExpressionKind::Quote(quote) => self.elaborate_quote(quote), + ExpressionKind::Comptime(comptime) => self.elaborate_comptime_block(comptime), + ExpressionKind::Error => (HirExpression::Error, Type::Error), + }; + let id = self.interner.push_expr(hir_expr); + self.interner.push_expr_location(id, expr.span, self.file); + self.interner.push_expr_type(id, typ.clone()); + (id, typ) + } + + pub(super) fn elaborate_block(&mut self, block: BlockExpression) -> (HirExpression, Type) { + self.push_scope(); + let mut block_type = Type::Unit; + let mut statements = Vec::with_capacity(block.statements.len()); + + for (i, statement) in block.statements.into_iter().enumerate() { + let (id, stmt_type) = self.elaborate_statement(statement); + statements.push(id); + + if let HirStatement::Semi(expr) = self.interner.statement(&id) { + let inner_expr_type = self.interner.id_type(expr); + let span = self.interner.expr_span(&expr); + + self.unify(&inner_expr_type, &Type::Unit, || TypeCheckError::UnusedResultError { + expr_type: inner_expr_type.clone(), + expr_span: span, + }); + + if i + 1 == statements.len() { + block_type = stmt_type; + } + } + } + + self.pop_scope(); + (HirExpression::Block(HirBlockExpression { statements }), block_type) + } + + fn elaborate_literal(&mut self, literal: Literal, span: Span) -> (HirExpression, Type) { + use HirExpression::Literal as Lit; + match literal { + Literal::Unit => (Lit(HirLiteral::Unit), Type::Unit), + Literal::Bool(b) => (Lit(HirLiteral::Bool(b)), Type::Bool), + Literal::Integer(integer, sign) => { + let int = HirLiteral::Integer(integer, sign); + (Lit(int), self.polymorphic_integer_or_field()) + } + Literal::Str(str) | Literal::RawStr(str, _) => { + let len = Type::Constant(str.len() as u64); + (Lit(HirLiteral::Str(str)), Type::String(Box::new(len))) + } + Literal::FmtStr(str) => self.elaborate_fmt_string(str, span), + Literal::Array(array_literal) => { + self.elaborate_array_literal(array_literal, span, true) + } + Literal::Slice(array_literal) => { + self.elaborate_array_literal(array_literal, span, false) + } + } + } + + fn elaborate_array_literal( + &mut self, + array_literal: ArrayLiteral, + span: Span, + is_array: bool, + ) -> (HirExpression, Type) { + let (expr, elem_type, length) = match array_literal { + ArrayLiteral::Standard(elements) => { + let first_elem_type = self.interner.next_type_variable(); + let first_span = elements.first().map(|elem| elem.span).unwrap_or(span); + + let elements = vecmap(elements.into_iter().enumerate(), |(i, elem)| { + let span = elem.span; + let (elem_id, elem_type) = self.elaborate_expression(elem); + + self.unify(&elem_type, &first_elem_type, || { + TypeCheckError::NonHomogeneousArray { + first_span, + first_type: first_elem_type.to_string(), + first_index: 0, + second_span: span, + second_type: elem_type.to_string(), + second_index: i, + } + .add_context("elements in an array must have the same type") + }); + elem_id + }); + + let length = Type::Constant(elements.len() as u64); + (HirArrayLiteral::Standard(elements), first_elem_type, length) + } + ArrayLiteral::Repeated { repeated_element, length } => { + let span = length.span; + let length = + UnresolvedTypeExpression::from_expr(*length, span).unwrap_or_else(|error| { + self.push_err(ResolverError::ParserError(Box::new(error))); + UnresolvedTypeExpression::Constant(0, span) + }); + + let length = self.convert_expression_type(length); + let (repeated_element, elem_type) = self.elaborate_expression(*repeated_element); + + let length_clone = length.clone(); + (HirArrayLiteral::Repeated { repeated_element, length }, elem_type, length_clone) + } + }; + let constructor = if is_array { HirLiteral::Array } else { HirLiteral::Slice }; + let elem_type = Box::new(elem_type); + let typ = if is_array { + Type::Array(Box::new(length), elem_type) + } else { + Type::Slice(elem_type) + }; + (HirExpression::Literal(constructor(expr)), typ) + } + + fn elaborate_fmt_string(&mut self, str: String, call_expr_span: Span) -> (HirExpression, Type) { + let re = Regex::new(r"\{([a-zA-Z0-9_]+)\}") + .expect("ICE: an invalid regex pattern was used for checking format strings"); + + let mut fmt_str_idents = Vec::new(); + let mut capture_types = Vec::new(); + + for field in re.find_iter(&str) { + let matched_str = field.as_str(); + let ident_name = &matched_str[1..(matched_str.len() - 1)]; + + let scope_tree = self.scopes.current_scope_tree(); + let variable = scope_tree.find(ident_name); + if let Some((old_value, _)) = variable { + old_value.num_times_used += 1; + let ident = HirExpression::Ident(old_value.ident.clone()); + let expr_id = self.interner.push_expr(ident); + self.interner.push_expr_location(expr_id, call_expr_span, self.file); + let ident = old_value.ident.clone(); + let typ = self.type_check_variable(ident, expr_id); + self.interner.push_expr_type(expr_id, typ.clone()); + capture_types.push(typ); + fmt_str_idents.push(expr_id); + } else if ident_name.parse::().is_ok() { + self.push_err(ResolverError::NumericConstantInFormatString { + name: ident_name.to_owned(), + span: call_expr_span, + }); + } else { + self.push_err(ResolverError::VariableNotDeclared { + name: ident_name.to_owned(), + span: call_expr_span, + }); + } + } + + let len = Type::Constant(str.len() as u64); + let typ = Type::FmtString(Box::new(len), Box::new(Type::Tuple(capture_types))); + (HirExpression::Literal(HirLiteral::FmtStr(str, fmt_str_idents)), typ) + } + + fn elaborate_prefix(&mut self, prefix: PrefixExpression) -> (HirExpression, Type) { + let span = prefix.rhs.span; + let (rhs, rhs_type) = self.elaborate_expression(prefix.rhs); + let ret_type = self.type_check_prefix_operand(&prefix.operator, &rhs_type, span); + (HirExpression::Prefix(HirPrefixExpression { operator: prefix.operator, rhs }), ret_type) + } + + fn elaborate_index(&mut self, index_expr: IndexExpression) -> (HirExpression, Type) { + let span = index_expr.index.span; + let (index, index_type) = self.elaborate_expression(index_expr.index); + + let expected = self.polymorphic_integer_or_field(); + self.unify(&index_type, &expected, || TypeCheckError::TypeMismatch { + expected_typ: "an integer".to_owned(), + expr_typ: index_type.to_string(), + expr_span: span, + }); + + // When writing `a[i]`, if `a : &mut ...` then automatically dereference `a` as many + // times as needed to get the underlying array. + let lhs_span = index_expr.collection.span; + let (lhs, lhs_type) = self.elaborate_expression(index_expr.collection); + let (collection, lhs_type) = self.insert_auto_dereferences(lhs, lhs_type); + + let typ = match lhs_type.follow_bindings() { + // XXX: We can check the array bounds here also, but it may be better to constant fold first + // and have ConstId instead of ExprId for constants + Type::Array(_, base_type) => *base_type, + Type::Slice(base_type) => *base_type, + Type::Error => Type::Error, + typ => { + self.push_err(TypeCheckError::TypeMismatch { + expected_typ: "Array".to_owned(), + expr_typ: typ.to_string(), + expr_span: lhs_span, + }); + Type::Error + } + }; + + let expr = HirExpression::Index(HirIndexExpression { collection, index }); + (expr, typ) + } + + fn elaborate_call(&mut self, call: CallExpression, span: Span) -> (HirExpression, Type) { + let (func, func_type) = self.elaborate_expression(*call.func); + + let mut arguments = Vec::with_capacity(call.arguments.len()); + let args = vecmap(call.arguments, |arg| { + let span = arg.span; + let (arg, typ) = self.elaborate_expression(arg); + arguments.push(arg); + (typ, arg, span) + }); + + let location = Location::new(span, self.file); + let call = HirCallExpression { func, arguments, location }; + let typ = self.type_check_call(&call, func_type, args, span); + (HirExpression::Call(call), typ) + } + + fn elaborate_method_call( + &mut self, + method_call: MethodCallExpression, + span: Span, + ) -> (HirExpression, Type) { + let object_span = method_call.object.span; + let (mut object, mut object_type) = self.elaborate_expression(method_call.object); + object_type = object_type.follow_bindings(); + + let method_name = method_call.method_name.0.contents.as_str(); + match self.lookup_method(&object_type, method_name, span) { + Some(method_ref) => { + // Automatically add `&mut` if the method expects a mutable reference and + // the object is not already one. + if let HirMethodReference::FuncId(func_id) = &method_ref { + if *func_id != FuncId::dummy_id() { + let function_type = self.interner.function_meta(func_id).typ.clone(); + + self.try_add_mutable_reference_to_object( + &function_type, + &mut object_type, + &mut object, + ); + } + } + + // These arguments will be given to the desugared function call. + // Compared to the method arguments, they also contain the object. + let mut function_args = Vec::with_capacity(method_call.arguments.len() + 1); + let mut arguments = Vec::with_capacity(method_call.arguments.len()); + + function_args.push((object_type.clone(), object, object_span)); + + for arg in method_call.arguments { + let span = arg.span; + let (arg, typ) = self.elaborate_expression(arg); + arguments.push(arg); + function_args.push((typ, arg, span)); + } + + let location = Location::new(span, self.file); + let method = method_call.method_name; + let method_call = HirMethodCallExpression { method, object, arguments, location }; + + // Desugar the method call into a normal, resolved function call + // so that the backend doesn't need to worry about methods + // TODO: update object_type here? + let ((function_id, function_name), function_call) = method_call.into_function_call( + &method_ref, + object_type, + location, + &mut self.interner, + ); + + let func_type = self.type_check_variable(function_name, function_id); + + // Type check the new call now that it has been changed from a method call + // to a function call. This way we avoid duplicating code. + let typ = self.type_check_call(&function_call, func_type, function_args, span); + (HirExpression::Call(function_call), typ) + } + None => (HirExpression::Error, Type::Error), + } + } + + fn elaborate_constructor( + &mut self, + constructor: ConstructorExpression, + ) -> (HirExpression, Type) { + let span = constructor.type_name.span(); + + match self.lookup_type_or_error(constructor.type_name) { + Some(Type::Struct(r#type, struct_generics)) => { + let struct_type = r#type.clone(); + let generics = struct_generics.clone(); + + let fields = constructor.fields; + let field_types = r#type.borrow().get_fields(&struct_generics); + let fields = self.resolve_constructor_expr_fields( + struct_type.clone(), + field_types, + fields, + span, + ); + let expr = HirExpression::Constructor(HirConstructorExpression { + fields, + r#type, + struct_generics, + }); + (expr, Type::Struct(struct_type, generics)) + } + Some(typ) => { + self.push_err(ResolverError::NonStructUsedInConstructor { typ, span }); + (HirExpression::Error, Type::Error) + } + None => (HirExpression::Error, Type::Error), + } + } + + /// Resolve all the fields of a struct constructor expression. + /// Ensures all fields are present, none are repeated, and all + /// are part of the struct. + fn resolve_constructor_expr_fields( + &mut self, + struct_type: Shared, + field_types: Vec<(String, Type)>, + fields: Vec<(Ident, Expression)>, + span: Span, + ) -> Vec<(Ident, ExprId)> { + let mut ret = Vec::with_capacity(fields.len()); + let mut seen_fields = HashSet::default(); + let mut unseen_fields = struct_type.borrow().field_names(); + + for (field_name, field) in fields { + let expected_type = field_types.iter().find(|(name, _)| name == &field_name.0.contents); + let expected_type = expected_type.map(|(_, typ)| typ).unwrap_or(&Type::Error); + + let field_span = field.span; + let (resolved, field_type) = self.elaborate_expression(field); + + if unseen_fields.contains(&field_name) { + unseen_fields.remove(&field_name); + seen_fields.insert(field_name.clone()); + + self.unify_with_coercions(&field_type, expected_type, resolved, || { + TypeCheckError::TypeMismatch { + expected_typ: expected_type.to_string(), + expr_typ: field_type.to_string(), + expr_span: field_span, + } + }); + } else if seen_fields.contains(&field_name) { + // duplicate field + self.push_err(ResolverError::DuplicateField { field: field_name.clone() }); + } else { + // field not required by struct + self.push_err(ResolverError::NoSuchField { + field: field_name.clone(), + struct_definition: struct_type.borrow().name.clone(), + }); + } + + ret.push((field_name, resolved)); + } + + if !unseen_fields.is_empty() { + self.push_err(ResolverError::MissingFields { + span, + missing_fields: unseen_fields.into_iter().map(|field| field.to_string()).collect(), + struct_definition: struct_type.borrow().name.clone(), + }); + } + + ret + } + + fn elaborate_member_access( + &mut self, + access: MemberAccessExpression, + span: Span, + ) -> (ExprId, Type) { + let (lhs, lhs_type) = self.elaborate_expression(access.lhs); + let rhs = access.rhs; + // `is_offset` is only used when lhs is a reference and we want to return a reference to rhs + let access = HirMemberAccess { lhs, rhs, is_offset: false }; + let expr_id = self.intern_expr(HirExpression::MemberAccess(access.clone()), span); + let typ = self.type_check_member_access(access, expr_id, lhs_type, span); + self.interner.push_expr_type(expr_id, typ.clone()); + (expr_id, typ) + } + + fn intern_expr(&mut self, expr: HirExpression, span: Span) -> ExprId { + let id = self.interner.push_expr(expr); + self.interner.push_expr_location(id, span, self.file); + id + } + + fn elaborate_cast(&mut self, cast: CastExpression, span: Span) -> (HirExpression, Type) { + let (lhs, lhs_type) = self.elaborate_expression(cast.lhs); + let r#type = self.resolve_type(cast.r#type); + let result = self.check_cast(lhs_type, &r#type, span); + let expr = HirExpression::Cast(HirCastExpression { lhs, r#type }); + (expr, result) + } + + fn elaborate_infix(&mut self, infix: InfixExpression, span: Span) -> (ExprId, Type) { + let (lhs, lhs_type) = self.elaborate_expression(infix.lhs); + let (rhs, rhs_type) = self.elaborate_expression(infix.rhs); + let trait_id = self.interner.get_operator_trait_method(infix.operator.contents); + + let operator = HirBinaryOp::new(infix.operator, self.file); + let expr = HirExpression::Infix(HirInfixExpression { + lhs, + operator, + trait_method_id: trait_id, + rhs, + }); + + let expr_id = self.interner.push_expr(expr); + self.interner.push_expr_location(expr_id, span, self.file); + + let typ = match self.infix_operand_type_rules(&lhs_type, &operator, &rhs_type, span) { + Ok((typ, use_impl)) => { + if use_impl { + // Delay checking the trait constraint until the end of the function. + // Checking it now could bind an unbound type variable to any type + // that implements the trait. + let constraint = TraitConstraint { + typ: lhs_type.clone(), + trait_id: trait_id.trait_id, + trait_generics: Vec::new(), + }; + self.trait_constraints.push((constraint, expr_id)); + self.type_check_operator_method(expr_id, trait_id, &lhs_type, span); + } + typ + } + Err(error) => { + self.push_err(error); + Type::Error + } + }; + + self.interner.push_expr_type(expr_id, typ.clone()); + (expr_id, typ) + } + + fn elaborate_if(&mut self, if_expr: IfExpression) -> (HirExpression, Type) { + let expr_span = if_expr.condition.span; + let (condition, cond_type) = self.elaborate_expression(if_expr.condition); + let (consequence, mut ret_type) = self.elaborate_expression(if_expr.consequence); + + self.unify(&cond_type, &Type::Bool, || TypeCheckError::TypeMismatch { + expected_typ: Type::Bool.to_string(), + expr_typ: cond_type.to_string(), + expr_span, + }); + + let alternative = if_expr.alternative.map(|alternative| { + let expr_span = alternative.span; + let (else_, else_type) = self.elaborate_expression(alternative); + + self.unify(&ret_type, &else_type, || { + let err = TypeCheckError::TypeMismatch { + expected_typ: ret_type.to_string(), + expr_typ: else_type.to_string(), + expr_span, + }; + + let context = if ret_type == Type::Unit { + "Are you missing a semicolon at the end of your 'else' branch?" + } else if else_type == Type::Unit { + "Are you missing a semicolon at the end of the first block of this 'if'?" + } else { + "Expected the types of both if branches to be equal" + }; + + err.add_context(context) + }); + else_ + }); + + if alternative.is_none() { + ret_type = Type::Unit; + } + + let if_expr = HirIfExpression { condition, consequence, alternative }; + (HirExpression::If(if_expr), ret_type) + } + + fn elaborate_tuple(&mut self, tuple: Vec) -> (HirExpression, Type) { + let mut element_ids = Vec::with_capacity(tuple.len()); + let mut element_types = Vec::with_capacity(tuple.len()); + + for element in tuple { + let (id, typ) = self.elaborate_expression(element); + element_ids.push(id); + element_types.push(typ); + } + + (HirExpression::Tuple(element_ids), Type::Tuple(element_types)) + } + + fn elaborate_lambda(&mut self, lambda: Lambda) -> (HirExpression, Type) { + self.push_scope(); + let scope_index = self.scopes.current_scope_index(); + + self.lambda_stack.push(LambdaContext { captures: Vec::new(), scope_index }); + + let mut arg_types = Vec::with_capacity(lambda.parameters.len()); + let parameters = vecmap(lambda.parameters, |(pattern, typ)| { + let parameter = DefinitionKind::Local(None); + let typ = self.resolve_inferred_type(typ); + arg_types.push(typ.clone()); + (self.elaborate_pattern(pattern, typ.clone(), parameter), typ) + }); + + let return_type = self.resolve_inferred_type(lambda.return_type); + let body_span = lambda.body.span; + let (body, body_type) = self.elaborate_expression(lambda.body); + + let lambda_context = self.lambda_stack.pop().unwrap(); + self.pop_scope(); + + self.unify(&body_type, &return_type, || TypeCheckError::TypeMismatch { + expected_typ: return_type.to_string(), + expr_typ: body_type.to_string(), + expr_span: body_span, + }); + + let captured_vars = vecmap(&lambda_context.captures, |capture| { + self.interner.definition_type(capture.ident.id) + }); + + let env_type = + if captured_vars.is_empty() { Type::Unit } else { Type::Tuple(captured_vars) }; + + let captures = lambda_context.captures; + let expr = HirExpression::Lambda(HirLambda { parameters, return_type, body, captures }); + (expr, Type::Function(arg_types, Box::new(body_type), Box::new(env_type))) + } + + fn elaborate_quote(&mut self, block: BlockExpression) -> (HirExpression, Type) { + (HirExpression::Quote(block), Type::Code) + } + + fn elaborate_comptime_block(&mut self, _comptime: BlockExpression) -> (HirExpression, Type) { + todo!("Elaborate comptime block") + } +} diff --git a/compiler/noirc_frontend/src/elaborator/mod.rs b/compiler/noirc_frontend/src/elaborator/mod.rs new file mode 100644 index 00000000000..9a34fa847f5 --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/mod.rs @@ -0,0 +1,159 @@ +#![allow(unused)] +use std::{ + collections::{BTreeMap, BTreeSet}, + rc::Rc, +}; + +use crate::graph::CrateId; +use crate::hir::def_map::CrateDefMap; +use crate::{ + ast::{ + ArrayLiteral, ConstructorExpression, FunctionKind, IfExpression, InfixExpression, Lambda, + UnresolvedTraitConstraint, UnresolvedTypeExpression, + }, + hir::{ + def_collector::dc_crate::CompilationError, + resolution::{errors::ResolverError, path_resolver::PathResolver, resolver::LambdaContext}, + scope::ScopeForest as GenericScopeForest, + type_check::TypeCheckError, + }, + hir_def::{ + expr::{ + HirArrayLiteral, HirBinaryOp, HirBlockExpression, HirCallExpression, HirCastExpression, + HirConstructorExpression, HirIdent, HirIfExpression, HirIndexExpression, + HirInfixExpression, HirLambda, HirMemberAccess, HirMethodCallExpression, + HirMethodReference, HirPrefixExpression, + }, + traits::TraitConstraint, + }, + macros_api::{ + BlockExpression, CallExpression, CastExpression, Expression, ExpressionKind, HirExpression, + HirLiteral, HirStatement, Ident, IndexExpression, Literal, MemberAccessExpression, + MethodCallExpression, NodeInterner, NoirFunction, PrefixExpression, Statement, + StatementKind, StructId, + }, + node_interner::{DefinitionKind, DependencyId, ExprId, FuncId, StmtId, TraitId}, + Shared, StructType, Type, TypeVariable, +}; + +mod expressions; +mod patterns; +mod scope; +mod statements; +mod types; + +use fm::FileId; +use iter_extended::vecmap; +use noirc_errors::{Location, Span}; +use regex::Regex; +use rustc_hash::FxHashSet as HashSet; + +/// ResolverMetas are tagged onto each definition to track how many times they are used +#[derive(Debug, PartialEq, Eq)] +struct ResolverMeta { + num_times_used: usize, + ident: HirIdent, + warn_if_unused: bool, +} + +type ScopeForest = GenericScopeForest; + +struct Elaborator { + scopes: ScopeForest, + + errors: Vec, + + interner: NodeInterner, + file: FileId, + + in_unconstrained_fn: bool, + nested_loops: usize, + + /// True if the current module is a contract. + /// This is usually determined by self.path_resolver.module_id(), but it can + /// be overridden for impls. Impls are an odd case since the methods within resolve + /// as if they're in the parent module, but should be placed in a child module. + /// Since they should be within a child module, in_contract is manually set to false + /// for these so we can still resolve them in the parent module without them being in a contract. + in_contract: bool, + + /// Contains a mapping of the current struct or functions's generics to + /// unique type variables if we're resolving a struct. Empty otherwise. + /// This is a Vec rather than a map to preserve the order a functions generics + /// were declared in. + generics: Vec<(Rc, TypeVariable, Span)>, + + /// When resolving lambda expressions, we need to keep track of the variables + /// that are captured. We do this in order to create the hidden environment + /// parameter for the lambda function. + lambda_stack: Vec, + + /// Set to the current type if we're resolving an impl + self_type: Option, + + /// The current dependency item we're resolving. + /// Used to link items to their dependencies in the dependency graph + current_item: Option, + + trait_id: Option, + + path_resolver: Rc, + def_maps: BTreeMap, + + /// In-resolution names + /// + /// This needs to be a set because we can have multiple in-resolution + /// names when resolving structs that are declared in reverse order of their + /// dependencies, such as in the following case: + /// + /// ``` + /// struct Wrapper { + /// value: Wrapped + /// } + /// struct Wrapped { + /// } + /// ``` + resolving_ids: BTreeSet, + + trait_bounds: Vec, + + current_function: Option, + + /// All type variables created in the current function. + /// This map is used to default any integer type variables at the end of + /// a function (before checking trait constraints) if a type wasn't already chosen. + type_variables: Vec, + + /// Trait constraints are collected during type checking until they are + /// verified at the end of a function. This is because constraints arise + /// on each variable, but it is only until function calls when the types + /// needed for the trait constraint may become known. + trait_constraints: Vec<(TraitConstraint, ExprId)>, +} + +impl Elaborator { + fn elaborate_function(&mut self, function: NoirFunction, _id: FuncId) { + // This is a stub until the elaborator is connected to dc_crate + match function.kind { + FunctionKind::LowLevel => todo!(), + FunctionKind::Builtin => todo!(), + FunctionKind::Oracle => todo!(), + FunctionKind::Recursive => todo!(), + FunctionKind::Normal => { + let _body = self.elaborate_block(function.def.body); + } + } + } + + fn push_scope(&mut self) { + // stub + } + + fn pop_scope(&mut self) { + // stub + } + + fn push_err(&mut self, error: impl Into) { + self.errors.push(error.into()); + } +} diff --git a/compiler/noirc_frontend/src/elaborator/patterns.rs b/compiler/noirc_frontend/src/elaborator/patterns.rs new file mode 100644 index 00000000000..b51115417e7 --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/patterns.rs @@ -0,0 +1,463 @@ +use iter_extended::vecmap; +use noirc_errors::{Location, Span}; +use rustc_hash::FxHashSet as HashSet; + +use crate::{ + ast::ERROR_IDENT, + hir::{ + resolution::errors::ResolverError, + type_check::{Source, TypeCheckError}, + }, + hir_def::{ + expr::{HirIdent, ImplKind}, + stmt::HirPattern, + }, + macros_api::{HirExpression, Ident, Path, Pattern}, + node_interner::{DefinitionId, DefinitionKind, ExprId, TraitImplKind}, + Shared, StructType, Type, TypeBindings, +}; + +use super::{Elaborator, ResolverMeta}; + +impl Elaborator { + pub(super) fn elaborate_pattern( + &mut self, + pattern: Pattern, + expected_type: Type, + definition_kind: DefinitionKind, + ) -> HirPattern { + self.elaborate_pattern_mut(pattern, expected_type, definition_kind, None) + } + + fn elaborate_pattern_mut( + &mut self, + pattern: Pattern, + expected_type: Type, + definition: DefinitionKind, + mutable: Option, + ) -> HirPattern { + match pattern { + Pattern::Identifier(name) => { + // If this definition is mutable, do not store the rhs because it will + // not always refer to the correct value of the variable + let definition = match (mutable, definition) { + (Some(_), DefinitionKind::Local(_)) => DefinitionKind::Local(None), + (_, other) => other, + }; + let ident = self.add_variable_decl(name, mutable.is_some(), true, definition); + self.interner.push_definition_type(ident.id, expected_type); + HirPattern::Identifier(ident) + } + Pattern::Mutable(pattern, span, _) => { + if let Some(first_mut) = mutable { + self.push_err(ResolverError::UnnecessaryMut { first_mut, second_mut: span }); + } + + let pattern = + self.elaborate_pattern_mut(*pattern, expected_type, definition, Some(span)); + let location = Location::new(span, self.file); + HirPattern::Mutable(Box::new(pattern), location) + } + Pattern::Tuple(fields, span) => { + let field_types = match expected_type { + Type::Tuple(fields) => fields, + Type::Error => Vec::new(), + expected_type => { + let tuple = + Type::Tuple(vecmap(&fields, |_| self.interner.next_type_variable())); + + self.push_err(TypeCheckError::TypeMismatchWithSource { + expected: expected_type, + actual: tuple, + span, + source: Source::Assignment, + }); + Vec::new() + } + }; + + let fields = vecmap(fields.into_iter().enumerate(), |(i, field)| { + let field_type = field_types.get(i).cloned().unwrap_or(Type::Error); + self.elaborate_pattern_mut(field, field_type, definition.clone(), mutable) + }); + let location = Location::new(span, self.file); + HirPattern::Tuple(fields, location) + } + Pattern::Struct(name, fields, span) => self.elaborate_struct_pattern( + name, + fields, + span, + expected_type, + definition, + mutable, + ), + } + } + + fn elaborate_struct_pattern( + &mut self, + name: Path, + fields: Vec<(Ident, Pattern)>, + span: Span, + expected_type: Type, + definition: DefinitionKind, + mutable: Option, + ) -> HirPattern { + let error_identifier = |this: &mut Self| { + // Must create a name here to return a HirPattern::Identifier. Allowing + // shadowing here lets us avoid further errors if we define ERROR_IDENT + // multiple times. + let name = ERROR_IDENT.into(); + let identifier = this.add_variable_decl(name, false, true, definition.clone()); + HirPattern::Identifier(identifier) + }; + + let (struct_type, generics) = match self.lookup_type_or_error(name) { + Some(Type::Struct(struct_type, generics)) => (struct_type, generics), + None => return error_identifier(self), + Some(typ) => { + self.push_err(ResolverError::NonStructUsedInConstructor { typ, span }); + return error_identifier(self); + } + }; + + let actual_type = Type::Struct(struct_type.clone(), generics); + let location = Location::new(span, self.file); + + self.unify(&actual_type, &expected_type, || TypeCheckError::TypeMismatchWithSource { + expected: expected_type.clone(), + actual: actual_type.clone(), + span: location.span, + source: Source::Assignment, + }); + + let typ = struct_type.clone(); + let fields = self.resolve_constructor_pattern_fields( + typ, + fields, + span, + expected_type.clone(), + definition, + mutable, + ); + + HirPattern::Struct(expected_type, fields, location) + } + + /// Resolve all the fields of a struct constructor expression. + /// Ensures all fields are present, none are repeated, and all + /// are part of the struct. + fn resolve_constructor_pattern_fields( + &mut self, + struct_type: Shared, + fields: Vec<(Ident, Pattern)>, + span: Span, + expected_type: Type, + definition: DefinitionKind, + mutable: Option, + ) -> Vec<(Ident, HirPattern)> { + let mut ret = Vec::with_capacity(fields.len()); + let mut seen_fields = HashSet::default(); + let mut unseen_fields = struct_type.borrow().field_names(); + + for (field, pattern) in fields { + let field_type = expected_type.get_field_type(&field.0.contents).unwrap_or(Type::Error); + let resolved = + self.elaborate_pattern_mut(pattern, field_type, definition.clone(), mutable); + + if unseen_fields.contains(&field) { + unseen_fields.remove(&field); + seen_fields.insert(field.clone()); + } else if seen_fields.contains(&field) { + // duplicate field + self.push_err(ResolverError::DuplicateField { field: field.clone() }); + } else { + // field not required by struct + self.push_err(ResolverError::NoSuchField { + field: field.clone(), + struct_definition: struct_type.borrow().name.clone(), + }); + } + + ret.push((field, resolved)); + } + + if !unseen_fields.is_empty() { + self.push_err(ResolverError::MissingFields { + span, + missing_fields: unseen_fields.into_iter().map(|field| field.to_string()).collect(), + struct_definition: struct_type.borrow().name.clone(), + }); + } + + ret + } + + pub(super) fn add_variable_decl( + &mut self, + name: Ident, + mutable: bool, + allow_shadowing: bool, + definition: DefinitionKind, + ) -> HirIdent { + self.add_variable_decl_inner(name, mutable, allow_shadowing, true, definition) + } + + fn add_variable_decl_inner( + &mut self, + name: Ident, + mutable: bool, + allow_shadowing: bool, + warn_if_unused: bool, + definition: DefinitionKind, + ) -> HirIdent { + if definition.is_global() { + return self.add_global_variable_decl(name, definition); + } + + let location = Location::new(name.span(), self.file); + let id = + self.interner.push_definition(name.0.contents.clone(), mutable, definition, location); + let ident = HirIdent::non_trait_method(id, location); + let resolver_meta = + ResolverMeta { num_times_used: 0, ident: ident.clone(), warn_if_unused }; + + let scope = self.scopes.get_mut_scope(); + let old_value = scope.add_key_value(name.0.contents.clone(), resolver_meta); + + if !allow_shadowing { + if let Some(old_value) = old_value { + self.push_err(ResolverError::DuplicateDefinition { + name: name.0.contents, + first_span: old_value.ident.location.span, + second_span: location.span, + }); + } + } + + ident + } + + fn add_global_variable_decl(&mut self, name: Ident, definition: DefinitionKind) -> HirIdent { + let scope = self.scopes.get_mut_scope(); + + // This check is necessary to maintain the same definition ids in the interner. Currently, each function uses a new resolver that has its own ScopeForest and thus global scope. + // We must first check whether an existing definition ID has been inserted as otherwise there will be multiple definitions for the same global statement. + // This leads to an error in evaluation where the wrong definition ID is selected when evaluating a statement using the global. The check below prevents this error. + let mut global_id = None; + let global = self.interner.get_all_globals(); + for global_info in global { + if global_info.ident == name + && global_info.local_id == self.path_resolver.local_module_id() + { + global_id = Some(global_info.id); + } + } + + let (ident, resolver_meta) = if let Some(id) = global_id { + let global = self.interner.get_global(id); + let hir_ident = HirIdent::non_trait_method(global.definition_id, global.location); + let ident = hir_ident.clone(); + let resolver_meta = ResolverMeta { num_times_used: 0, ident, warn_if_unused: true }; + (hir_ident, resolver_meta) + } else { + let location = Location::new(name.span(), self.file); + let id = + self.interner.push_definition(name.0.contents.clone(), false, definition, location); + let ident = HirIdent::non_trait_method(id, location); + let resolver_meta = + ResolverMeta { num_times_used: 0, ident: ident.clone(), warn_if_unused: true }; + (ident, resolver_meta) + }; + + let old_global_value = scope.add_key_value(name.0.contents.clone(), resolver_meta); + if let Some(old_global_value) = old_global_value { + self.push_err(ResolverError::DuplicateDefinition { + name: name.0.contents.clone(), + first_span: old_global_value.ident.location.span, + second_span: name.span(), + }); + } + ident + } + + // Checks for a variable having been declared before. + // (Variable declaration and definition cannot be separate in Noir.) + // Once the variable has been found, intern and link `name` to this definition, + // returning (the ident, the IdentId of `name`) + // + // If a variable is not found, then an error is logged and a dummy id + // is returned, for better error reporting UX + pub(super) fn find_variable_or_default(&mut self, name: &Ident) -> (HirIdent, usize) { + self.use_variable(name).unwrap_or_else(|error| { + self.push_err(error); + let id = DefinitionId::dummy_id(); + let location = Location::new(name.span(), self.file); + (HirIdent::non_trait_method(id, location), 0) + }) + } + + /// Lookup and use the specified variable. + /// This will increment its use counter by one and return the variable if found. + /// If the variable is not found, an error is returned. + pub(super) fn use_variable( + &mut self, + name: &Ident, + ) -> Result<(HirIdent, usize), ResolverError> { + // Find the definition for this Ident + let scope_tree = self.scopes.current_scope_tree(); + let variable = scope_tree.find(&name.0.contents); + + let location = Location::new(name.span(), self.file); + if let Some((variable_found, scope)) = variable { + variable_found.num_times_used += 1; + let id = variable_found.ident.id; + Ok((HirIdent::non_trait_method(id, location), scope)) + } else { + Err(ResolverError::VariableNotDeclared { + name: name.0.contents.clone(), + span: name.0.span(), + }) + } + } + + pub(super) fn elaborate_variable(&mut self, variable: Path) -> (ExprId, Type) { + let span = variable.span; + let expr = self.resolve_variable(variable); + let id = self.interner.push_expr(HirExpression::Ident(expr.clone())); + self.interner.push_expr_location(id, span, self.file); + let typ = self.type_check_variable(expr, id); + self.interner.push_expr_type(id, typ.clone()); + (id, typ) + } + + fn resolve_variable(&mut self, path: Path) -> HirIdent { + if let Some((method, constraint, assumed)) = self.resolve_trait_generic_path(&path) { + HirIdent { + location: Location::new(path.span, self.file), + id: self.interner.trait_method_id(method), + impl_kind: ImplKind::TraitMethod(method, constraint, assumed), + } + } else { + // If the Path is being used as an Expression, then it is referring to a global from a separate module + // Otherwise, then it is referring to an Identifier + // This lookup allows support of such statements: let x = foo::bar::SOME_GLOBAL + 10; + // If the expression is a singular indent, we search the resolver's current scope as normal. + let (hir_ident, var_scope_index) = self.get_ident_from_path(path); + + if hir_ident.id != DefinitionId::dummy_id() { + match self.interner.definition(hir_ident.id).kind { + DefinitionKind::Function(id) => { + if let Some(current_item) = self.current_item { + self.interner.add_function_dependency(current_item, id); + } + } + DefinitionKind::Global(global_id) => { + if let Some(current_item) = self.current_item { + self.interner.add_global_dependency(current_item, global_id); + } + } + DefinitionKind::GenericType(_) => { + // Initialize numeric generics to a polymorphic integer type in case + // they're used in expressions. We must do this here since type_check_variable + // does not check definition kinds and otherwise expects parameters to + // already be typed. + if self.interner.definition_type(hir_ident.id) == Type::Error { + let typ = Type::polymorphic_integer_or_field(&mut self.interner); + self.interner.push_definition_type(hir_ident.id, typ); + } + } + DefinitionKind::Local(_) => { + // only local variables can be captured by closures. + self.resolve_local_variable(hir_ident.clone(), var_scope_index); + } + } + } + + hir_ident + } + } + + pub(super) fn type_check_variable(&mut self, ident: HirIdent, expr_id: ExprId) -> Type { + let mut bindings = TypeBindings::new(); + + // Add type bindings from any constraints that were used. + // We need to do this first since otherwise instantiating the type below + // will replace each trait generic with a fresh type variable, rather than + // the type used in the trait constraint (if it exists). See #4088. + if let ImplKind::TraitMethod(_, constraint, _) = &ident.impl_kind { + let the_trait = self.interner.get_trait(constraint.trait_id); + assert_eq!(the_trait.generics.len(), constraint.trait_generics.len()); + + for (param, arg) in the_trait.generics.iter().zip(&constraint.trait_generics) { + // Avoid binding t = t + if !arg.occurs(param.id()) { + bindings.insert(param.id(), (param.clone(), arg.clone())); + } + } + } + + // An identifiers type may be forall-quantified in the case of generic functions. + // E.g. `fn foo(t: T, field: Field) -> T` has type `forall T. fn(T, Field) -> T`. + // We must instantiate identifiers at every call site to replace this T with a new type + // variable to handle generic functions. + let t = self.interner.id_type_substitute_trait_as_type(ident.id); + + // This instantiates a trait's generics as well which need to be set + // when the constraint below is later solved for when the function is + // finished. How to link the two? + let (typ, bindings) = t.instantiate_with_bindings(bindings, &self.interner); + + // Push any trait constraints required by this definition to the context + // to be checked later when the type of this variable is further constrained. + if let Some(definition) = self.interner.try_definition(ident.id) { + if let DefinitionKind::Function(function) = definition.kind { + let function = self.interner.function_meta(&function); + + for mut constraint in function.trait_constraints.clone() { + constraint.apply_bindings(&bindings); + self.trait_constraints.push((constraint, expr_id)); + } + } + } + + if let ImplKind::TraitMethod(_, mut constraint, assumed) = ident.impl_kind { + constraint.apply_bindings(&bindings); + if assumed { + let trait_impl = TraitImplKind::Assumed { + object_type: constraint.typ, + trait_generics: constraint.trait_generics, + }; + self.interner.select_impl_for_expression(expr_id, trait_impl); + } else { + // Currently only one impl can be selected per expr_id, so this + // constraint needs to be pushed after any other constraints so + // that monomorphization can resolve this trait method to the correct impl. + self.trait_constraints.push((constraint, expr_id)); + } + } + + self.interner.store_instantiation_bindings(expr_id, bindings); + typ + } + + fn get_ident_from_path(&mut self, path: Path) -> (HirIdent, usize) { + let location = Location::new(path.span(), self.file); + + let error = match path.as_ident().map(|ident| self.use_variable(ident)) { + Some(Ok(found)) => return found, + // Try to look it up as a global, but still issue the first error if we fail + Some(Err(error)) => match self.lookup_global(path) { + Ok(id) => return (HirIdent::non_trait_method(id, location), 0), + Err(_) => error, + }, + None => match self.lookup_global(path) { + Ok(id) => return (HirIdent::non_trait_method(id, location), 0), + Err(error) => error, + }, + }; + self.push_err(error); + let id = DefinitionId::dummy_id(); + (HirIdent::non_trait_method(id, location), 0) + } +} diff --git a/compiler/noirc_frontend/src/elaborator/scope.rs b/compiler/noirc_frontend/src/elaborator/scope.rs new file mode 100644 index 00000000000..e8baba6bd89 --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/scope.rs @@ -0,0 +1,100 @@ +use rustc_hash::FxHashMap as HashMap; + +use crate::hir::comptime::Value; +use crate::{ + hir::{ + def_map::{ModuleDefId, TryFromModuleDefId}, + resolution::errors::ResolverError, + }, + hir_def::{ + expr::{HirCapturedVar, HirIdent}, + traits::Trait, + }, + macros_api::{Path, StructId}, + node_interner::{DefinitionId, TraitId, TypeAliasId}, + Shared, StructType, +}; + +use super::Elaborator; + +impl Elaborator { + pub(super) fn lookup(&mut self, path: Path) -> Result { + let span = path.span(); + let id = self.resolve_path(path)?; + T::try_from(id).ok_or_else(|| ResolverError::Expected { + expected: T::description(), + got: id.as_str().to_owned(), + span, + }) + } + + pub(super) fn resolve_path(&mut self, path: Path) -> Result { + let path_resolution = self.path_resolver.resolve(&self.def_maps, path)?; + + if let Some(error) = path_resolution.error { + self.push_err(error); + } + + Ok(path_resolution.module_def_id) + } + + pub(super) fn get_struct(&self, type_id: StructId) -> Shared { + self.interner.get_struct(type_id) + } + + pub(super) fn get_trait_mut(&mut self, trait_id: TraitId) -> &mut Trait { + self.interner.get_trait_mut(trait_id) + } + + pub(super) fn resolve_local_variable(&mut self, hir_ident: HirIdent, var_scope_index: usize) { + let mut transitive_capture_index: Option = None; + + for lambda_index in 0..self.lambda_stack.len() { + if self.lambda_stack[lambda_index].scope_index > var_scope_index { + // Beware: the same variable may be captured multiple times, so we check + // for its presence before adding the capture below. + let position = self.lambda_stack[lambda_index] + .captures + .iter() + .position(|capture| capture.ident.id == hir_ident.id); + + if position.is_none() { + self.lambda_stack[lambda_index].captures.push(HirCapturedVar { + ident: hir_ident.clone(), + transitive_capture_index, + }); + } + + if lambda_index + 1 < self.lambda_stack.len() { + // There is more than one closure between the current scope and + // the scope of the variable, so this is a propagated capture. + // We need to track the transitive capture index as we go up in + // the closure stack. + transitive_capture_index = Some(position.unwrap_or( + // If this was a fresh capture, we added it to the end of + // the captures vector: + self.lambda_stack[lambda_index].captures.len() - 1, + )); + } + } + } + } + + pub(super) fn lookup_global(&mut self, path: Path) -> Result { + let span = path.span(); + let id = self.resolve_path(path)?; + + if let Some(function) = TryFromModuleDefId::try_from(id) { + return Ok(self.interner.function_definition_id(function)); + } + + if let Some(global) = TryFromModuleDefId::try_from(id) { + let global = self.interner.get_global(global); + return Ok(global.definition_id); + } + + let expected = "global variable".into(); + let got = "local variable".into(); + Err(ResolverError::Expected { span, expected, got }) + } +} diff --git a/compiler/noirc_frontend/src/elaborator/statements.rs b/compiler/noirc_frontend/src/elaborator/statements.rs new file mode 100644 index 00000000000..6ad6d66b2d4 --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/statements.rs @@ -0,0 +1,409 @@ +use noirc_errors::{Location, Span}; + +use crate::{ + ast::{AssignStatement, ConstrainStatement, LValue}, + hir::{ + resolution::errors::ResolverError, + type_check::{Source, TypeCheckError}, + }, + hir_def::{ + expr::HirIdent, + stmt::{ + HirAssignStatement, HirConstrainStatement, HirForStatement, HirLValue, HirLetStatement, + }, + }, + macros_api::{ + ForLoopStatement, ForRange, HirStatement, LetStatement, Statement, StatementKind, + }, + node_interner::{DefinitionId, DefinitionKind, StmtId}, + Type, +}; + +use super::Elaborator; + +impl Elaborator { + fn elaborate_statement_value(&mut self, statement: Statement) -> (HirStatement, Type) { + match statement.kind { + StatementKind::Let(let_stmt) => self.elaborate_let(let_stmt), + StatementKind::Constrain(constrain) => self.elaborate_constrain(constrain), + StatementKind::Assign(assign) => self.elaborate_assign(assign), + StatementKind::For(for_stmt) => self.elaborate_for(for_stmt), + StatementKind::Break => self.elaborate_jump(true, statement.span), + StatementKind::Continue => self.elaborate_jump(false, statement.span), + StatementKind::Comptime(statement) => self.elaborate_comptime(*statement), + StatementKind::Expression(expr) => { + let (expr, typ) = self.elaborate_expression(expr); + (HirStatement::Expression(expr), typ) + } + StatementKind::Semi(expr) => { + let (expr, _typ) = self.elaborate_expression(expr); + (HirStatement::Semi(expr), Type::Unit) + } + StatementKind::Error => (HirStatement::Error, Type::Error), + } + } + + pub(super) fn elaborate_statement(&mut self, statement: Statement) -> (StmtId, Type) { + let span = statement.span; + let (hir_statement, typ) = self.elaborate_statement_value(statement); + let id = self.interner.push_stmt(hir_statement); + self.interner.push_stmt_location(id, span, self.file); + (id, typ) + } + + pub(super) fn elaborate_let(&mut self, let_stmt: LetStatement) -> (HirStatement, Type) { + let expr_span = let_stmt.expression.span; + let (expression, expr_type) = self.elaborate_expression(let_stmt.expression); + let definition = DefinitionKind::Local(Some(expression)); + let annotated_type = self.resolve_type(let_stmt.r#type); + + // First check if the LHS is unspecified + // If so, then we give it the same type as the expression + let r#type = if annotated_type != Type::Error { + // Now check if LHS is the same type as the RHS + // Importantly, we do not coerce any types implicitly + self.unify_with_coercions(&expr_type, &annotated_type, expression, || { + TypeCheckError::TypeMismatch { + expected_typ: annotated_type.to_string(), + expr_typ: expr_type.to_string(), + expr_span, + } + }); + if annotated_type.is_unsigned() { + self.lint_overflowing_uint(&expression, &annotated_type); + } + annotated_type + } else { + expr_type + }; + + let let_ = HirLetStatement { + pattern: self.elaborate_pattern(let_stmt.pattern, r#type.clone(), definition), + r#type, + expression, + attributes: let_stmt.attributes, + comptime: let_stmt.comptime, + }; + (HirStatement::Let(let_), Type::Unit) + } + + pub(super) fn elaborate_constrain(&mut self, stmt: ConstrainStatement) -> (HirStatement, Type) { + let expr_span = stmt.0.span; + let (expr_id, expr_type) = self.elaborate_expression(stmt.0); + + // Must type check the assertion message expression so that we instantiate bindings + let msg = stmt.1.map(|assert_msg_expr| self.elaborate_expression(assert_msg_expr).0); + + self.unify(&expr_type, &Type::Bool, || TypeCheckError::TypeMismatch { + expr_typ: expr_type.to_string(), + expected_typ: Type::Bool.to_string(), + expr_span, + }); + + (HirStatement::Constrain(HirConstrainStatement(expr_id, self.file, msg)), Type::Unit) + } + + pub(super) fn elaborate_assign(&mut self, assign: AssignStatement) -> (HirStatement, Type) { + let span = assign.expression.span; + let (expression, expr_type) = self.elaborate_expression(assign.expression); + let (lvalue, lvalue_type, mutable) = self.elaborate_lvalue(assign.lvalue, span); + + if !mutable { + let (name, span) = self.get_lvalue_name_and_span(&lvalue); + self.push_err(TypeCheckError::VariableMustBeMutable { name, span }); + } + + self.unify_with_coercions(&expr_type, &lvalue_type, expression, || { + TypeCheckError::TypeMismatchWithSource { + actual: expr_type.clone(), + expected: lvalue_type.clone(), + span, + source: Source::Assignment, + } + }); + + let stmt = HirAssignStatement { lvalue, expression }; + (HirStatement::Assign(stmt), Type::Unit) + } + + pub(super) fn elaborate_for(&mut self, for_loop: ForLoopStatement) -> (HirStatement, Type) { + let (start, end) = match for_loop.range { + ForRange::Range(start, end) => (start, end), + ForRange::Array(_) => { + let for_stmt = + for_loop.range.into_for(for_loop.identifier, for_loop.block, for_loop.span); + + return self.elaborate_statement_value(for_stmt); + } + }; + + let start_span = start.span; + let end_span = end.span; + + let (start_range, start_range_type) = self.elaborate_expression(start); + let (end_range, end_range_type) = self.elaborate_expression(end); + let (identifier, block) = (for_loop.identifier, for_loop.block); + + self.nested_loops += 1; + self.push_scope(); + + // TODO: For loop variables are currently mutable by default since we haven't + // yet implemented syntax for them to be optionally mutable. + let kind = DefinitionKind::Local(None); + let identifier = self.add_variable_decl(identifier, false, true, kind); + + // Check that start range and end range have the same types + let range_span = start_span.merge(end_span); + self.unify(&start_range_type, &end_range_type, || TypeCheckError::TypeMismatch { + expected_typ: start_range_type.to_string(), + expr_typ: end_range_type.to_string(), + expr_span: range_span, + }); + + let expected_type = self.polymorphic_integer(); + + self.unify(&start_range_type, &expected_type, || TypeCheckError::TypeCannotBeUsed { + typ: start_range_type.clone(), + place: "for loop", + span: range_span, + }); + + self.interner.push_definition_type(identifier.id, start_range_type); + + let (block, _block_type) = self.elaborate_expression(block); + + self.pop_scope(); + self.nested_loops -= 1; + + let statement = + HirStatement::For(HirForStatement { start_range, end_range, block, identifier }); + + (statement, Type::Unit) + } + + fn elaborate_jump(&mut self, is_break: bool, span: noirc_errors::Span) -> (HirStatement, Type) { + if !self.in_unconstrained_fn { + self.push_err(ResolverError::JumpInConstrainedFn { is_break, span }); + } + if self.nested_loops == 0 { + self.push_err(ResolverError::JumpOutsideLoop { is_break, span }); + } + + let expr = if is_break { HirStatement::Break } else { HirStatement::Continue }; + (expr, self.interner.next_type_variable()) + } + + fn get_lvalue_name_and_span(&self, lvalue: &HirLValue) -> (String, Span) { + match lvalue { + HirLValue::Ident(name, _) => { + let span = name.location.span; + + if let Some(definition) = self.interner.try_definition(name.id) { + (definition.name.clone(), span) + } else { + ("(undeclared variable)".into(), span) + } + } + HirLValue::MemberAccess { object, .. } => self.get_lvalue_name_and_span(object), + HirLValue::Index { array, .. } => self.get_lvalue_name_and_span(array), + HirLValue::Dereference { lvalue, .. } => self.get_lvalue_name_and_span(lvalue), + } + } + + fn elaborate_lvalue(&mut self, lvalue: LValue, assign_span: Span) -> (HirLValue, Type, bool) { + match lvalue { + LValue::Ident(ident) => { + let mut mutable = true; + let (ident, scope_index) = self.find_variable_or_default(&ident); + self.resolve_local_variable(ident.clone(), scope_index); + + let typ = if ident.id == DefinitionId::dummy_id() { + Type::Error + } else { + if let Some(definition) = self.interner.try_definition(ident.id) { + mutable = definition.mutable; + } + + let typ = self.interner.definition_type(ident.id).instantiate(&self.interner).0; + typ.follow_bindings() + }; + + (HirLValue::Ident(ident.clone(), typ.clone()), typ, mutable) + } + LValue::MemberAccess { object, field_name, span } => { + let (object, lhs_type, mut mutable) = self.elaborate_lvalue(*object, assign_span); + let mut object = Box::new(object); + let field_name = field_name.clone(); + + let object_ref = &mut object; + let mutable_ref = &mut mutable; + let location = Location::new(span, self.file); + + let dereference_lhs = move |_: &mut Self, _, element_type| { + // We must create a temporary value first to move out of object_ref before + // we eventually reassign to it. + let id = DefinitionId::dummy_id(); + let ident = HirIdent::non_trait_method(id, location); + let tmp_value = HirLValue::Ident(ident, Type::Error); + + let lvalue = std::mem::replace(object_ref, Box::new(tmp_value)); + *object_ref = + Box::new(HirLValue::Dereference { lvalue, element_type, location }); + *mutable_ref = true; + }; + + let name = &field_name.0.contents; + let (object_type, field_index) = self + .check_field_access(&lhs_type, name, field_name.span(), Some(dereference_lhs)) + .unwrap_or((Type::Error, 0)); + + let field_index = Some(field_index); + let typ = object_type.clone(); + let lvalue = + HirLValue::MemberAccess { object, field_name, field_index, typ, location }; + (lvalue, object_type, mutable) + } + LValue::Index { array, index, span } => { + let expr_span = index.span; + let (index, index_type) = self.elaborate_expression(index); + let location = Location::new(span, self.file); + + let expected = self.polymorphic_integer_or_field(); + self.unify(&index_type, &expected, || TypeCheckError::TypeMismatch { + expected_typ: "an integer".to_owned(), + expr_typ: index_type.to_string(), + expr_span, + }); + + let (mut lvalue, mut lvalue_type, mut mutable) = + self.elaborate_lvalue(*array, assign_span); + + // Before we check that the lvalue is an array, try to dereference it as many times + // as needed to unwrap any &mut wrappers. + while let Type::MutableReference(element) = lvalue_type.follow_bindings() { + let element_type = element.as_ref().clone(); + lvalue = + HirLValue::Dereference { lvalue: Box::new(lvalue), element_type, location }; + lvalue_type = *element; + // We know this value to be mutable now since we found an `&mut` + mutable = true; + } + + let typ = match lvalue_type.follow_bindings() { + Type::Array(_, elem_type) => *elem_type, + Type::Slice(elem_type) => *elem_type, + Type::Error => Type::Error, + Type::String(_) => { + let (_lvalue_name, lvalue_span) = self.get_lvalue_name_and_span(&lvalue); + self.push_err(TypeCheckError::StringIndexAssign { span: lvalue_span }); + Type::Error + } + other => { + // TODO: Need a better span here + self.push_err(TypeCheckError::TypeMismatch { + expected_typ: "array".to_string(), + expr_typ: other.to_string(), + expr_span: assign_span, + }); + Type::Error + } + }; + + let array = Box::new(lvalue); + let array_type = typ.clone(); + (HirLValue::Index { array, index, typ, location }, array_type, mutable) + } + LValue::Dereference(lvalue, span) => { + let (lvalue, reference_type, _) = self.elaborate_lvalue(*lvalue, assign_span); + let lvalue = Box::new(lvalue); + let location = Location::new(span, self.file); + + let element_type = Type::type_variable(self.interner.next_type_variable_id()); + let expected_type = Type::MutableReference(Box::new(element_type.clone())); + + self.unify(&reference_type, &expected_type, || TypeCheckError::TypeMismatch { + expected_typ: expected_type.to_string(), + expr_typ: reference_type.to_string(), + expr_span: assign_span, + }); + + // Dereferences are always mutable since we already type checked against a &mut T + let typ = element_type.clone(); + let lvalue = HirLValue::Dereference { lvalue, element_type, location }; + (lvalue, typ, true) + } + } + } + + /// Type checks a field access, adding dereference operators as necessary + pub(super) fn check_field_access( + &mut self, + lhs_type: &Type, + field_name: &str, + span: Span, + dereference_lhs: Option, + ) -> Option<(Type, usize)> { + let lhs_type = lhs_type.follow_bindings(); + + match &lhs_type { + Type::Struct(s, args) => { + let s = s.borrow(); + if let Some((field, index)) = s.get_field(field_name, args) { + return Some((field, index)); + } + } + Type::Tuple(elements) => { + if let Ok(index) = field_name.parse::() { + let length = elements.len(); + if index < length { + return Some((elements[index].clone(), index)); + } else { + self.push_err(TypeCheckError::TupleIndexOutOfBounds { + index, + lhs_type, + length, + span, + }); + return None; + } + } + } + // If the lhs is a mutable reference we automatically transform + // lhs.field into (*lhs).field + Type::MutableReference(element) => { + if let Some(mut dereference_lhs) = dereference_lhs { + dereference_lhs(self, lhs_type.clone(), element.as_ref().clone()); + return self.check_field_access( + element, + field_name, + span, + Some(dereference_lhs), + ); + } else { + let (element, index) = + self.check_field_access(element, field_name, span, dereference_lhs)?; + return Some((Type::MutableReference(Box::new(element)), index)); + } + } + _ => (), + } + + // If we get here the type has no field named 'access.rhs'. + // Now we specialize the error message based on whether we know the object type in question yet. + if let Type::TypeVariable(..) = &lhs_type { + self.push_err(TypeCheckError::TypeAnnotationsNeeded { span }); + } else if lhs_type != Type::Error { + self.push_err(TypeCheckError::AccessUnknownMember { + lhs_type, + field_name: field_name.to_string(), + span, + }); + } + + None + } + + pub(super) fn elaborate_comptime(&self, _statement: Statement) -> (HirStatement, Type) { + todo!("Comptime scanning") + } +} diff --git a/compiler/noirc_frontend/src/elaborator/types.rs b/compiler/noirc_frontend/src/elaborator/types.rs new file mode 100644 index 00000000000..2cd699b919d --- /dev/null +++ b/compiler/noirc_frontend/src/elaborator/types.rs @@ -0,0 +1,1399 @@ +use std::rc::Rc; + +use iter_extended::vecmap; +use noirc_errors::{Location, Span}; + +use crate::{ + ast::{BinaryOpKind, IntegerBitSize, UnresolvedTraitConstraint, UnresolvedTypeExpression}, + hir::{ + def_map::ModuleDefId, + resolution::{ + errors::ResolverError, + import::PathResolution, + resolver::{verify_mutable_reference, SELF_TYPE_NAME}, + }, + type_check::{Source, TypeCheckError}, + }, + hir_def::{ + expr::{ + HirBinaryOp, HirCallExpression, HirIdent, HirMemberAccess, HirMethodReference, + HirPrefixExpression, + }, + traits::{Trait, TraitConstraint}, + }, + macros_api::{ + HirExpression, HirLiteral, Path, PathKind, SecondaryAttribute, Signedness, UnaryOp, + UnresolvedType, UnresolvedTypeData, + }, + node_interner::{DefinitionKind, ExprId, GlobalId, TraitImplKind, TraitMethodId}, + Generics, Shared, StructType, Type, TypeAlias, TypeBinding, TypeVariable, TypeVariableKind, +}; + +use super::Elaborator; + +impl Elaborator { + /// Translates an UnresolvedType to a Type + pub(super) fn resolve_type(&mut self, typ: UnresolvedType) -> Type { + let span = typ.span; + let resolved_type = self.resolve_type_inner(typ, &mut vec![]); + if resolved_type.is_nested_slice() { + self.push_err(ResolverError::NestedSlices { span: span.unwrap() }); + } + + resolved_type + } + + /// Translates an UnresolvedType into a Type and appends any + /// freshly created TypeVariables created to new_variables. + fn resolve_type_inner(&mut self, typ: UnresolvedType, new_variables: &mut Generics) -> Type { + use crate::ast::UnresolvedTypeData::*; + + let resolved_type = match typ.typ { + FieldElement => Type::FieldElement, + Array(size, elem) => { + let elem = Box::new(self.resolve_type_inner(*elem, new_variables)); + let size = self.resolve_array_size(Some(size), new_variables); + Type::Array(Box::new(size), elem) + } + Slice(elem) => { + let elem = Box::new(self.resolve_type_inner(*elem, new_variables)); + Type::Slice(elem) + } + Expression(expr) => self.convert_expression_type(expr), + Integer(sign, bits) => Type::Integer(sign, bits), + Bool => Type::Bool, + String(size) => { + let resolved_size = self.resolve_array_size(size, new_variables); + Type::String(Box::new(resolved_size)) + } + FormatString(size, fields) => { + let resolved_size = self.convert_expression_type(size); + let fields = self.resolve_type_inner(*fields, new_variables); + Type::FmtString(Box::new(resolved_size), Box::new(fields)) + } + Code => Type::Code, + Unit => Type::Unit, + Unspecified => Type::Error, + Error => Type::Error, + Named(path, args, _) => self.resolve_named_type(path, args, new_variables), + TraitAsType(path, args) => self.resolve_trait_as_type(path, args, new_variables), + + Tuple(fields) => { + Type::Tuple(vecmap(fields, |field| self.resolve_type_inner(field, new_variables))) + } + Function(args, ret, env) => { + let args = vecmap(args, |arg| self.resolve_type_inner(arg, new_variables)); + let ret = Box::new(self.resolve_type_inner(*ret, new_variables)); + + // expect() here is valid, because the only places we don't have a span are omitted types + // e.g. a function without return type implicitly has a spanless UnresolvedType::Unit return type + // To get an invalid env type, the user must explicitly specify the type, which will have a span + let env_span = + env.span.expect("Unexpected missing span for closure environment type"); + + let env = Box::new(self.resolve_type_inner(*env, new_variables)); + + match *env { + Type::Unit | Type::Tuple(_) | Type::NamedGeneric(_, _) => { + Type::Function(args, ret, env) + } + _ => { + self.push_err(ResolverError::InvalidClosureEnvironment { + typ: *env, + span: env_span, + }); + Type::Error + } + } + } + MutableReference(element) => { + Type::MutableReference(Box::new(self.resolve_type_inner(*element, new_variables))) + } + Parenthesized(typ) => self.resolve_type_inner(*typ, new_variables), + }; + + if let Type::Struct(_, _) = resolved_type { + if let Some(unresolved_span) = typ.span { + // Record the location of the type reference + self.interner.push_type_ref_location( + resolved_type.clone(), + Location::new(unresolved_span, self.file), + ); + } + } + resolved_type + } + + fn find_generic(&self, target_name: &str) -> Option<&(Rc, TypeVariable, Span)> { + self.generics.iter().find(|(name, _, _)| name.as_ref() == target_name) + } + + fn resolve_named_type( + &mut self, + path: Path, + args: Vec, + new_variables: &mut Generics, + ) -> Type { + if args.is_empty() { + if let Some(typ) = self.lookup_generic_or_global_type(&path) { + return typ; + } + } + + // Check if the path is a type variable first. We currently disallow generics on type + // variables since we do not support higher-kinded types. + if path.segments.len() == 1 { + let name = &path.last_segment().0.contents; + + if name == SELF_TYPE_NAME { + if let Some(self_type) = self.self_type.clone() { + if !args.is_empty() { + self.push_err(ResolverError::GenericsOnSelfType { span: path.span() }); + } + return self_type; + } + } + } + + let span = path.span(); + let mut args = vecmap(args, |arg| self.resolve_type_inner(arg, new_variables)); + + if let Some(type_alias) = self.lookup_type_alias(path.clone()) { + let type_alias = type_alias.borrow(); + let expected_generic_count = type_alias.generics.len(); + let type_alias_string = type_alias.to_string(); + let id = type_alias.id; + + self.verify_generics_count(expected_generic_count, &mut args, span, || { + type_alias_string + }); + + if let Some(item) = self.current_item { + self.interner.add_type_alias_dependency(item, id); + } + + // Collecting Type Alias references [Location]s to be used by LSP in order + // to resolve the definition of the type alias + self.interner.add_type_alias_ref(id, Location::new(span, self.file)); + + // Because there is no ordering to when type aliases (and other globals) are resolved, + // it is possible for one to refer to an Error type and issue no error if it is set + // equal to another type alias. Fixing this fully requires an analysis to create a DFG + // of definition ordering, but for now we have an explicit check here so that we at + // least issue an error that the type was not found instead of silently passing. + let alias = self.interner.get_type_alias(id); + return Type::Alias(alias, args); + } + + match self.lookup_struct_or_error(path) { + Some(struct_type) => { + if self.resolving_ids.contains(&struct_type.borrow().id) { + self.push_err(ResolverError::SelfReferentialStruct { + span: struct_type.borrow().name.span(), + }); + + return Type::Error; + } + + let expected_generic_count = struct_type.borrow().generics.len(); + if !self.in_contract + && self + .interner + .struct_attributes(&struct_type.borrow().id) + .iter() + .any(|attr| matches!(attr, SecondaryAttribute::Abi(_))) + { + self.push_err(ResolverError::AbiAttributeOutsideContract { + span: struct_type.borrow().name.span(), + }); + } + self.verify_generics_count(expected_generic_count, &mut args, span, || { + struct_type.borrow().to_string() + }); + + if let Some(current_item) = self.current_item { + let dependency_id = struct_type.borrow().id; + self.interner.add_type_dependency(current_item, dependency_id); + } + + Type::Struct(struct_type, args) + } + None => Type::Error, + } + } + + fn resolve_trait_as_type( + &mut self, + path: Path, + args: Vec, + new_variables: &mut Generics, + ) -> Type { + let args = vecmap(args, |arg| self.resolve_type_inner(arg, new_variables)); + + if let Some(t) = self.lookup_trait_or_error(path) { + Type::TraitAsType(t.id, Rc::new(t.name.to_string()), args) + } else { + Type::Error + } + } + + fn verify_generics_count( + &mut self, + expected_count: usize, + args: &mut Vec, + span: Span, + type_name: impl FnOnce() -> String, + ) { + if args.len() != expected_count { + self.push_err(ResolverError::IncorrectGenericCount { + span, + item_name: type_name(), + actual: args.len(), + expected: expected_count, + }); + + // Fix the generic count so we can continue typechecking + args.resize_with(expected_count, || Type::Error); + } + } + + fn lookup_generic_or_global_type(&mut self, path: &Path) -> Option { + if path.segments.len() == 1 { + let name = &path.last_segment().0.contents; + if let Some((name, var, _)) = self.find_generic(name) { + return Some(Type::NamedGeneric(var.clone(), name.clone())); + } + } + + // If we cannot find a local generic of the same name, try to look up a global + match self.path_resolver.resolve(&self.def_maps, path.clone()) { + Ok(PathResolution { module_def_id: ModuleDefId::GlobalId(id), error }) => { + if let Some(current_item) = self.current_item { + self.interner.add_global_dependency(current_item, id); + } + + if let Some(error) = error { + self.push_err(error); + } + Some(Type::Constant(self.eval_global_as_array_length(id, path))) + } + _ => None, + } + } + + fn resolve_array_size( + &mut self, + length: Option, + new_variables: &mut Generics, + ) -> Type { + match length { + None => { + let id = self.interner.next_type_variable_id(); + let typevar = TypeVariable::unbound(id); + new_variables.push(typevar.clone()); + + // 'Named'Generic is a bit of a misnomer here, we want a type variable that + // wont be bound over but this one has no name since we do not currently + // require users to explicitly be generic over array lengths. + Type::NamedGeneric(typevar, Rc::new("".into())) + } + Some(length) => self.convert_expression_type(length), + } + } + + pub(super) fn convert_expression_type(&mut self, length: UnresolvedTypeExpression) -> Type { + match length { + UnresolvedTypeExpression::Variable(path) => { + self.lookup_generic_or_global_type(&path).unwrap_or_else(|| { + self.push_err(ResolverError::NoSuchNumericTypeVariable { path }); + Type::Constant(0) + }) + } + UnresolvedTypeExpression::Constant(int, _) => Type::Constant(int), + UnresolvedTypeExpression::BinaryOperation(lhs, op, rhs, _) => { + let (lhs_span, rhs_span) = (lhs.span(), rhs.span()); + let lhs = self.convert_expression_type(*lhs); + let rhs = self.convert_expression_type(*rhs); + + match (lhs, rhs) { + (Type::Constant(lhs), Type::Constant(rhs)) => { + Type::Constant(op.function()(lhs, rhs)) + } + (lhs, _) => { + let span = + if !matches!(lhs, Type::Constant(_)) { lhs_span } else { rhs_span }; + self.push_err(ResolverError::InvalidArrayLengthExpr { span }); + Type::Constant(0) + } + } + } + } + } + + /// Lookup a given struct type by name. + fn lookup_struct_or_error(&mut self, path: Path) -> Option> { + match self.lookup(path) { + Ok(struct_id) => Some(self.get_struct(struct_id)), + Err(error) => { + self.push_err(error); + None + } + } + } + + /// Lookup a given trait by name/path. + fn lookup_trait_or_error(&mut self, path: Path) -> Option<&mut Trait> { + match self.lookup(path) { + Ok(trait_id) => Some(self.get_trait_mut(trait_id)), + Err(error) => { + self.push_err(error); + None + } + } + } + + /// Looks up a given type by name. + /// This will also instantiate any struct types found. + pub(super) fn lookup_type_or_error(&mut self, path: Path) -> Option { + let ident = path.as_ident(); + if ident.map_or(false, |i| i == SELF_TYPE_NAME) { + if let Some(typ) = &self.self_type { + return Some(typ.clone()); + } + } + + match self.lookup(path) { + Ok(struct_id) => { + let struct_type = self.get_struct(struct_id); + let generics = struct_type.borrow().instantiate(&mut self.interner); + Some(Type::Struct(struct_type, generics)) + } + Err(error) => { + self.push_err(error); + None + } + } + } + + fn lookup_type_alias(&mut self, path: Path) -> Option> { + self.lookup(path).ok().map(|id| self.interner.get_type_alias(id)) + } + + // this resolves Self::some_static_method, inside an impl block (where we don't have a concrete self_type) + // + // Returns the trait method, trait constraint, and whether the impl is assumed to exist by a where clause or not + // E.g. `t.method()` with `where T: Foo` in scope will return `(Foo::method, T, vec![Bar])` + fn resolve_trait_static_method_by_self( + &mut self, + path: &Path, + ) -> Option<(TraitMethodId, TraitConstraint, bool)> { + let trait_id = self.trait_id?; + + if path.kind == PathKind::Plain && path.segments.len() == 2 { + let name = &path.segments[0].0.contents; + let method = &path.segments[1]; + + if name == SELF_TYPE_NAME { + let the_trait = self.interner.get_trait(trait_id); + let method = the_trait.find_method(method.0.contents.as_str())?; + + let constraint = TraitConstraint { + typ: self.self_type.clone()?, + trait_generics: Type::from_generics(&the_trait.generics), + trait_id, + }; + return Some((method, constraint, false)); + } + } + None + } + + // this resolves TraitName::some_static_method + // + // Returns the trait method, trait constraint, and whether the impl is assumed to exist by a where clause or not + // E.g. `t.method()` with `where T: Foo` in scope will return `(Foo::method, T, vec![Bar])` + fn resolve_trait_static_method( + &mut self, + path: &Path, + ) -> Option<(TraitMethodId, TraitConstraint, bool)> { + if path.kind == PathKind::Plain && path.segments.len() == 2 { + let method = &path.segments[1]; + + let mut trait_path = path.clone(); + trait_path.pop(); + let trait_id = self.lookup(trait_path).ok()?; + let the_trait = self.interner.get_trait(trait_id); + + let method = the_trait.find_method(method.0.contents.as_str())?; + let constraint = TraitConstraint { + typ: Type::TypeVariable( + the_trait.self_type_typevar.clone(), + TypeVariableKind::Normal, + ), + trait_generics: Type::from_generics(&the_trait.generics), + trait_id, + }; + return Some((method, constraint, false)); + } + None + } + + // This resolves a static trait method T::trait_method by iterating over the where clause + // + // Returns the trait method, trait constraint, and whether the impl is assumed from a where + // clause. This is always true since this helper searches where clauses for a generic constraint. + // E.g. `t.method()` with `where T: Foo` in scope will return `(Foo::method, T, vec![Bar])` + fn resolve_trait_method_by_named_generic( + &mut self, + path: &Path, + ) -> Option<(TraitMethodId, TraitConstraint, bool)> { + if path.segments.len() != 2 { + return None; + } + + for UnresolvedTraitConstraint { typ, trait_bound } in self.trait_bounds.clone() { + if let UnresolvedTypeData::Named(constraint_path, _, _) = &typ.typ { + // if `path` is `T::method_name`, we're looking for constraint of the form `T: SomeTrait` + if constraint_path.segments.len() == 1 + && path.segments[0] != constraint_path.last_segment() + { + continue; + } + + if let Ok(ModuleDefId::TraitId(trait_id)) = + self.resolve_path(trait_bound.trait_path.clone()) + { + let the_trait = self.interner.get_trait(trait_id); + if let Some(method) = + the_trait.find_method(path.segments.last().unwrap().0.contents.as_str()) + { + let constraint = TraitConstraint { + trait_id, + typ: self.resolve_type(typ.clone()), + trait_generics: vecmap(trait_bound.trait_generics, |typ| { + self.resolve_type(typ) + }), + }; + return Some((method, constraint, true)); + } + } + } + } + None + } + + // Try to resolve the given trait method path. + // + // Returns the trait method, trait constraint, and whether the impl is assumed to exist by a where clause or not + // E.g. `t.method()` with `where T: Foo` in scope will return `(Foo::method, T, vec![Bar])` + pub(super) fn resolve_trait_generic_path( + &mut self, + path: &Path, + ) -> Option<(TraitMethodId, TraitConstraint, bool)> { + self.resolve_trait_static_method_by_self(path) + .or_else(|| self.resolve_trait_static_method(path)) + .or_else(|| self.resolve_trait_method_by_named_generic(path)) + } + + fn eval_global_as_array_length(&mut self, global: GlobalId, path: &Path) -> u64 { + let Some(stmt) = self.interner.get_global_let_statement(global) else { + let path = path.clone(); + self.push_err(ResolverError::NoSuchNumericTypeVariable { path }); + return 0; + }; + + let length = stmt.expression; + let span = self.interner.expr_span(&length); + let result = self.try_eval_array_length_id(length, span); + + match result.map(|length| length.try_into()) { + Ok(Ok(length_value)) => return length_value, + Ok(Err(_cast_err)) => self.push_err(ResolverError::IntegerTooLarge { span }), + Err(Some(error)) => self.push_err(error), + Err(None) => (), + } + 0 + } + + fn try_eval_array_length_id( + &self, + rhs: ExprId, + span: Span, + ) -> Result> { + // Arbitrary amount of recursive calls to try before giving up + let fuel = 100; + self.try_eval_array_length_id_with_fuel(rhs, span, fuel) + } + + fn try_eval_array_length_id_with_fuel( + &self, + rhs: ExprId, + span: Span, + fuel: u32, + ) -> Result> { + if fuel == 0 { + // If we reach here, it is likely from evaluating cyclic globals. We expect an error to + // be issued for them after name resolution so issue no error now. + return Err(None); + } + + match self.interner.expression(&rhs) { + HirExpression::Literal(HirLiteral::Integer(int, false)) => { + int.try_into_u128().ok_or(Some(ResolverError::IntegerTooLarge { span })) + } + HirExpression::Ident(ident) => { + let definition = self.interner.definition(ident.id); + match definition.kind { + DefinitionKind::Global(global_id) => { + let let_statement = self.interner.get_global_let_statement(global_id); + if let Some(let_statement) = let_statement { + let expression = let_statement.expression; + self.try_eval_array_length_id_with_fuel(expression, span, fuel - 1) + } else { + Err(Some(ResolverError::InvalidArrayLengthExpr { span })) + } + } + _ => Err(Some(ResolverError::InvalidArrayLengthExpr { span })), + } + } + HirExpression::Infix(infix) => { + let lhs = self.try_eval_array_length_id_with_fuel(infix.lhs, span, fuel - 1)?; + let rhs = self.try_eval_array_length_id_with_fuel(infix.rhs, span, fuel - 1)?; + + match infix.operator.kind { + BinaryOpKind::Add => Ok(lhs + rhs), + BinaryOpKind::Subtract => Ok(lhs - rhs), + BinaryOpKind::Multiply => Ok(lhs * rhs), + BinaryOpKind::Divide => Ok(lhs / rhs), + BinaryOpKind::Equal => Ok((lhs == rhs) as u128), + BinaryOpKind::NotEqual => Ok((lhs != rhs) as u128), + BinaryOpKind::Less => Ok((lhs < rhs) as u128), + BinaryOpKind::LessEqual => Ok((lhs <= rhs) as u128), + BinaryOpKind::Greater => Ok((lhs > rhs) as u128), + BinaryOpKind::GreaterEqual => Ok((lhs >= rhs) as u128), + BinaryOpKind::And => Ok(lhs & rhs), + BinaryOpKind::Or => Ok(lhs | rhs), + BinaryOpKind::Xor => Ok(lhs ^ rhs), + BinaryOpKind::ShiftRight => Ok(lhs >> rhs), + BinaryOpKind::ShiftLeft => Ok(lhs << rhs), + BinaryOpKind::Modulo => Ok(lhs % rhs), + } + } + _other => Err(Some(ResolverError::InvalidArrayLengthExpr { span })), + } + } + + /// Check if an assignment is overflowing with respect to `annotated_type` + /// in a declaration statement where `annotated_type` is an unsigned integer + pub(super) fn lint_overflowing_uint(&mut self, rhs_expr: &ExprId, annotated_type: &Type) { + let expr = self.interner.expression(rhs_expr); + let span = self.interner.expr_span(rhs_expr); + match expr { + HirExpression::Literal(HirLiteral::Integer(value, false)) => { + let v = value.to_u128(); + if let Type::Integer(_, bit_count) = annotated_type { + let bit_count: u32 = (*bit_count).into(); + let max = 1 << bit_count; + if v >= max { + self.push_err(TypeCheckError::OverflowingAssignment { + expr: value, + ty: annotated_type.clone(), + range: format!("0..={}", max - 1), + span, + }); + }; + }; + } + HirExpression::Prefix(expr) => { + self.lint_overflowing_uint(&expr.rhs, annotated_type); + if matches!(expr.operator, UnaryOp::Minus) { + self.push_err(TypeCheckError::InvalidUnaryOp { + kind: "annotated_type".to_string(), + span, + }); + } + } + HirExpression::Infix(expr) => { + self.lint_overflowing_uint(&expr.lhs, annotated_type); + self.lint_overflowing_uint(&expr.rhs, annotated_type); + } + _ => {} + } + } + + pub(super) fn unify( + &mut self, + actual: &Type, + expected: &Type, + make_error: impl FnOnce() -> TypeCheckError, + ) { + let mut errors = Vec::new(); + actual.unify(expected, &mut errors, make_error); + self.errors.extend(errors.into_iter().map(Into::into)); + } + + /// Wrapper of Type::unify_with_coercions using self.errors + pub(super) fn unify_with_coercions( + &mut self, + actual: &Type, + expected: &Type, + expression: ExprId, + make_error: impl FnOnce() -> TypeCheckError, + ) { + let mut errors = Vec::new(); + actual.unify_with_coercions( + expected, + expression, + &mut self.interner, + &mut errors, + make_error, + ); + self.errors.extend(errors.into_iter().map(Into::into)); + } + + /// Return a fresh integer or field type variable and log it + /// in self.type_variables to default it later. + pub(super) fn polymorphic_integer_or_field(&mut self) -> Type { + let typ = Type::polymorphic_integer_or_field(&mut self.interner); + self.type_variables.push(typ.clone()); + typ + } + + /// Return a fresh integer type variable and log it + /// in self.type_variables to default it later. + pub(super) fn polymorphic_integer(&mut self) -> Type { + let typ = Type::polymorphic_integer(&mut self.interner); + self.type_variables.push(typ.clone()); + typ + } + + /// Translates a (possibly Unspecified) UnresolvedType to a Type. + /// Any UnresolvedType::Unspecified encountered are replaced with fresh type variables. + pub(super) fn resolve_inferred_type(&mut self, typ: UnresolvedType) -> Type { + match &typ.typ { + UnresolvedTypeData::Unspecified => self.interner.next_type_variable(), + _ => self.resolve_type_inner(typ, &mut vec![]), + } + } + + pub(super) fn type_check_prefix_operand( + &mut self, + op: &crate::ast::UnaryOp, + rhs_type: &Type, + span: Span, + ) -> Type { + let mut unify = |this: &mut Self, expected| { + this.unify(rhs_type, &expected, || TypeCheckError::TypeMismatch { + expr_typ: rhs_type.to_string(), + expected_typ: expected.to_string(), + expr_span: span, + }); + expected + }; + + match op { + crate::ast::UnaryOp::Minus => { + if rhs_type.is_unsigned() { + self.push_err(TypeCheckError::InvalidUnaryOp { + kind: rhs_type.to_string(), + span, + }); + } + let expected = self.polymorphic_integer_or_field(); + self.unify(rhs_type, &expected, || TypeCheckError::InvalidUnaryOp { + kind: rhs_type.to_string(), + span, + }); + expected + } + crate::ast::UnaryOp::Not => { + let rhs_type = rhs_type.follow_bindings(); + + // `!` can work on booleans or integers + if matches!(rhs_type, Type::Integer(..)) { + return rhs_type; + } + + unify(self, Type::Bool) + } + crate::ast::UnaryOp::MutableReference => { + Type::MutableReference(Box::new(rhs_type.follow_bindings())) + } + crate::ast::UnaryOp::Dereference { implicitly_added: _ } => { + let element_type = self.interner.next_type_variable(); + unify(self, Type::MutableReference(Box::new(element_type.clone()))); + element_type + } + } + } + + /// Insert as many dereference operations as necessary to automatically dereference a method + /// call object to its base value type T. + pub(super) fn insert_auto_dereferences(&mut self, object: ExprId, typ: Type) -> (ExprId, Type) { + if let Type::MutableReference(element) = typ { + let location = self.interner.id_location(object); + + let object = self.interner.push_expr(HirExpression::Prefix(HirPrefixExpression { + operator: UnaryOp::Dereference { implicitly_added: true }, + rhs: object, + })); + self.interner.push_expr_type(object, element.as_ref().clone()); + self.interner.push_expr_location(object, location.span, location.file); + + // Recursively dereference to allow for converting &mut &mut T to T + self.insert_auto_dereferences(object, *element) + } else { + (object, typ) + } + } + + /// Given a method object: `(*foo).bar` of a method call `(*foo).bar.baz()`, remove the + /// implicitly added dereference operator if one is found. + /// + /// Returns Some(new_expr_id) if a dereference was removed and None otherwise. + fn try_remove_implicit_dereference(&mut self, object: ExprId) -> Option { + match self.interner.expression(&object) { + HirExpression::MemberAccess(mut access) => { + let new_lhs = self.try_remove_implicit_dereference(access.lhs)?; + access.lhs = new_lhs; + access.is_offset = true; + + // `object` will have a different type now, which will be filled in + // later when type checking the method call as a function call. + self.interner.replace_expr(&object, HirExpression::MemberAccess(access)); + Some(object) + } + HirExpression::Prefix(prefix) => match prefix.operator { + // Found a dereference we can remove. Now just replace it with its rhs to remove it. + UnaryOp::Dereference { implicitly_added: true } => Some(prefix.rhs), + _ => None, + }, + _ => None, + } + } + + fn bind_function_type_impl( + &mut self, + fn_params: &[Type], + fn_ret: &Type, + callsite_args: &[(Type, ExprId, Span)], + span: Span, + ) -> Type { + if fn_params.len() != callsite_args.len() { + self.push_err(TypeCheckError::ParameterCountMismatch { + expected: fn_params.len(), + found: callsite_args.len(), + span, + }); + return Type::Error; + } + + for (param, (arg, _, arg_span)) in fn_params.iter().zip(callsite_args) { + self.unify(arg, param, || TypeCheckError::TypeMismatch { + expected_typ: param.to_string(), + expr_typ: arg.to_string(), + expr_span: *arg_span, + }); + } + + fn_ret.clone() + } + + pub(super) fn bind_function_type( + &mut self, + function: Type, + args: Vec<(Type, ExprId, Span)>, + span: Span, + ) -> Type { + // Could do a single unification for the entire function type, but matching beforehand + // lets us issue a more precise error on the individual argument that fails to type check. + match function { + Type::TypeVariable(binding, TypeVariableKind::Normal) => { + if let TypeBinding::Bound(typ) = &*binding.borrow() { + return self.bind_function_type(typ.clone(), args, span); + } + + let ret = self.interner.next_type_variable(); + let args = vecmap(args, |(arg, _, _)| arg); + let env_type = self.interner.next_type_variable(); + let expected = Type::Function(args, Box::new(ret.clone()), Box::new(env_type)); + + if let Err(error) = binding.try_bind(expected, span) { + self.push_err(error); + } + ret + } + // The closure env is ignored on purpose: call arguments never place + // constraints on closure environments. + Type::Function(parameters, ret, _env) => { + self.bind_function_type_impl(¶meters, &ret, &args, span) + } + Type::Error => Type::Error, + found => { + self.push_err(TypeCheckError::ExpectedFunction { found, span }); + Type::Error + } + } + } + + pub(super) fn check_cast(&mut self, from: Type, to: &Type, span: Span) -> Type { + match from.follow_bindings() { + Type::Integer(..) + | Type::FieldElement + | Type::TypeVariable(_, TypeVariableKind::IntegerOrField) + | Type::TypeVariable(_, TypeVariableKind::Integer) + | Type::Bool => (), + + Type::TypeVariable(_, _) => { + self.push_err(TypeCheckError::TypeAnnotationsNeeded { span }); + return Type::Error; + } + Type::Error => return Type::Error, + from => { + self.push_err(TypeCheckError::InvalidCast { from, span }); + return Type::Error; + } + } + + match to { + Type::Integer(sign, bits) => Type::Integer(*sign, *bits), + Type::FieldElement => Type::FieldElement, + Type::Bool => Type::Bool, + Type::Error => Type::Error, + _ => { + self.push_err(TypeCheckError::UnsupportedCast { span }); + Type::Error + } + } + } + + // Given a binary comparison operator and another type. This method will produce the output type + // and a boolean indicating whether to use the trait impl corresponding to the operator + // or not. A value of false indicates the caller to use a primitive operation for this + // operator, while a true value indicates a user-provided trait impl is required. + fn comparator_operand_type_rules( + &mut self, + lhs_type: &Type, + rhs_type: &Type, + op: &HirBinaryOp, + span: Span, + ) -> Result<(Type, bool), TypeCheckError> { + use Type::*; + + match (lhs_type, rhs_type) { + // Avoid reporting errors multiple times + (Error, _) | (_, Error) => Ok((Bool, false)), + (Alias(alias, args), other) | (other, Alias(alias, args)) => { + let alias = alias.borrow().get_type(args); + self.comparator_operand_type_rules(&alias, other, op, span) + } + + // Matches on TypeVariable must be first to follow any type + // bindings. + (TypeVariable(var, _), other) | (other, TypeVariable(var, _)) => { + if let TypeBinding::Bound(binding) = &*var.borrow() { + return self.comparator_operand_type_rules(other, binding, op, span); + } + + let use_impl = self.bind_type_variables_for_infix(lhs_type, op, rhs_type, span); + Ok((Bool, use_impl)) + } + (Integer(sign_x, bit_width_x), Integer(sign_y, bit_width_y)) => { + if sign_x != sign_y { + return Err(TypeCheckError::IntegerSignedness { + sign_x: *sign_x, + sign_y: *sign_y, + span, + }); + } + if bit_width_x != bit_width_y { + return Err(TypeCheckError::IntegerBitWidth { + bit_width_x: *bit_width_x, + bit_width_y: *bit_width_y, + span, + }); + } + Ok((Bool, false)) + } + (FieldElement, FieldElement) => { + if op.kind.is_valid_for_field_type() { + Ok((Bool, false)) + } else { + Err(TypeCheckError::FieldComparison { span }) + } + } + + // <= and friends are technically valid for booleans, just not very useful + (Bool, Bool) => Ok((Bool, false)), + + (lhs, rhs) => { + self.unify(lhs, rhs, || TypeCheckError::TypeMismatchWithSource { + expected: lhs.clone(), + actual: rhs.clone(), + span: op.location.span, + source: Source::Binary, + }); + Ok((Bool, true)) + } + } + } + + /// Handles the TypeVariable case for checking binary operators. + /// Returns true if we should use the impl for the operator instead of the primitive + /// version of it. + fn bind_type_variables_for_infix( + &mut self, + lhs_type: &Type, + op: &HirBinaryOp, + rhs_type: &Type, + span: Span, + ) -> bool { + self.unify(lhs_type, rhs_type, || TypeCheckError::TypeMismatchWithSource { + expected: lhs_type.clone(), + actual: rhs_type.clone(), + source: Source::Binary, + span, + }); + + let use_impl = !lhs_type.is_numeric(); + + // If this operator isn't valid for fields we have to possibly narrow + // TypeVariableKind::IntegerOrField to TypeVariableKind::Integer. + // Doing so also ensures a type error if Field is used. + // The is_numeric check is to allow impls for custom types to bypass this. + if !op.kind.is_valid_for_field_type() && lhs_type.is_numeric() { + let target = Type::polymorphic_integer(&mut self.interner); + + use crate::ast::BinaryOpKind::*; + use TypeCheckError::*; + self.unify(lhs_type, &target, || match op.kind { + Less | LessEqual | Greater | GreaterEqual => FieldComparison { span }, + And | Or | Xor | ShiftRight | ShiftLeft => FieldBitwiseOp { span }, + Modulo => FieldModulo { span }, + other => unreachable!("Operator {other:?} should be valid for Field"), + }); + } + + use_impl + } + + // Given a binary operator and another type. This method will produce the output type + // and a boolean indicating whether to use the trait impl corresponding to the operator + // or not. A value of false indicates the caller to use a primitive operation for this + // operator, while a true value indicates a user-provided trait impl is required. + pub(super) fn infix_operand_type_rules( + &mut self, + lhs_type: &Type, + op: &HirBinaryOp, + rhs_type: &Type, + span: Span, + ) -> Result<(Type, bool), TypeCheckError> { + if op.kind.is_comparator() { + return self.comparator_operand_type_rules(lhs_type, rhs_type, op, span); + } + + use Type::*; + match (lhs_type, rhs_type) { + // An error type on either side will always return an error + (Error, _) | (_, Error) => Ok((Error, false)), + (Alias(alias, args), other) | (other, Alias(alias, args)) => { + let alias = alias.borrow().get_type(args); + self.infix_operand_type_rules(&alias, op, other, span) + } + + // Matches on TypeVariable must be first so that we follow any type + // bindings. + (TypeVariable(int, _), other) | (other, TypeVariable(int, _)) => { + if let TypeBinding::Bound(binding) = &*int.borrow() { + return self.infix_operand_type_rules(binding, op, other, span); + } + if op.kind == BinaryOpKind::ShiftLeft || op.kind == BinaryOpKind::ShiftRight { + self.unify( + rhs_type, + &Type::Integer(Signedness::Unsigned, IntegerBitSize::Eight), + || TypeCheckError::InvalidShiftSize { span }, + ); + let use_impl = if lhs_type.is_numeric() { + let integer_type = Type::polymorphic_integer(&mut self.interner); + self.bind_type_variables_for_infix(lhs_type, op, &integer_type, span) + } else { + true + }; + return Ok((lhs_type.clone(), use_impl)); + } + let use_impl = self.bind_type_variables_for_infix(lhs_type, op, rhs_type, span); + Ok((other.clone(), use_impl)) + } + (Integer(sign_x, bit_width_x), Integer(sign_y, bit_width_y)) => { + if op.kind == BinaryOpKind::ShiftLeft || op.kind == BinaryOpKind::ShiftRight { + if *sign_y != Signedness::Unsigned || *bit_width_y != IntegerBitSize::Eight { + return Err(TypeCheckError::InvalidShiftSize { span }); + } + return Ok((Integer(*sign_x, *bit_width_x), false)); + } + if sign_x != sign_y { + return Err(TypeCheckError::IntegerSignedness { + sign_x: *sign_x, + sign_y: *sign_y, + span, + }); + } + if bit_width_x != bit_width_y { + return Err(TypeCheckError::IntegerBitWidth { + bit_width_x: *bit_width_x, + bit_width_y: *bit_width_y, + span, + }); + } + Ok((Integer(*sign_x, *bit_width_x), false)) + } + // The result of two Fields is always a witness + (FieldElement, FieldElement) => { + if !op.kind.is_valid_for_field_type() { + if op.kind == BinaryOpKind::Modulo { + return Err(TypeCheckError::FieldModulo { span }); + } else { + return Err(TypeCheckError::FieldBitwiseOp { span }); + } + } + Ok((FieldElement, false)) + } + + (Bool, Bool) => Ok((Bool, false)), + + (lhs, rhs) => { + if op.kind == BinaryOpKind::ShiftLeft || op.kind == BinaryOpKind::ShiftRight { + if rhs == &Type::Integer(Signedness::Unsigned, IntegerBitSize::Eight) { + return Ok((lhs.clone(), true)); + } + return Err(TypeCheckError::InvalidShiftSize { span }); + } + self.unify(lhs, rhs, || TypeCheckError::TypeMismatchWithSource { + expected: lhs.clone(), + actual: rhs.clone(), + span: op.location.span, + source: Source::Binary, + }); + Ok((lhs.clone(), true)) + } + } + } + + /// Prerequisite: verify_trait_constraint of the operator's trait constraint. + /// + /// Although by this point the operator is expected to already have a trait impl, + /// we still need to match the operator's type against the method's instantiated type + /// to ensure the instantiation bindings are correct and the monomorphizer can + /// re-apply the needed bindings. + pub(super) fn type_check_operator_method( + &mut self, + expr_id: ExprId, + trait_method_id: TraitMethodId, + object_type: &Type, + span: Span, + ) { + let the_trait = self.interner.get_trait(trait_method_id.trait_id); + + let method = &the_trait.methods[trait_method_id.method_index]; + let (method_type, mut bindings) = method.typ.clone().instantiate(&self.interner); + + match method_type { + Type::Function(args, _, _) => { + // We can cheat a bit and match against only the object type here since no operator + // overload uses other generic parameters or return types aside from the object type. + let expected_object_type = &args[0]; + self.unify(object_type, expected_object_type, || TypeCheckError::TypeMismatch { + expected_typ: expected_object_type.to_string(), + expr_typ: object_type.to_string(), + expr_span: span, + }); + } + other => { + unreachable!("Expected operator method to have a function type, but found {other}") + } + } + + // We must also remember to apply these substitutions to the object_type + // referenced by the selected trait impl, if one has yet to be selected. + let impl_kind = self.interner.get_selected_impl_for_expression(expr_id); + if let Some(TraitImplKind::Assumed { object_type, trait_generics }) = impl_kind { + let the_trait = self.interner.get_trait(trait_method_id.trait_id); + let object_type = object_type.substitute(&bindings); + bindings.insert( + the_trait.self_type_typevar_id, + (the_trait.self_type_typevar.clone(), object_type.clone()), + ); + self.interner.select_impl_for_expression( + expr_id, + TraitImplKind::Assumed { object_type, trait_generics }, + ); + } + + self.interner.store_instantiation_bindings(expr_id, bindings); + } + + pub(super) fn type_check_member_access( + &mut self, + mut access: HirMemberAccess, + expr_id: ExprId, + lhs_type: Type, + span: Span, + ) -> Type { + let access_lhs = &mut access.lhs; + + let dereference_lhs = |this: &mut Self, lhs_type, element| { + let old_lhs = *access_lhs; + *access_lhs = this.interner.push_expr(HirExpression::Prefix(HirPrefixExpression { + operator: crate::ast::UnaryOp::Dereference { implicitly_added: true }, + rhs: old_lhs, + })); + this.interner.push_expr_type(old_lhs, lhs_type); + this.interner.push_expr_type(*access_lhs, element); + + let old_location = this.interner.id_location(old_lhs); + this.interner.push_expr_location(*access_lhs, span, old_location.file); + }; + + // If this access is just a field offset, we want to avoid dereferencing + let dereference_lhs = (!access.is_offset).then_some(dereference_lhs); + + match self.check_field_access(&lhs_type, &access.rhs.0.contents, span, dereference_lhs) { + Some((element_type, index)) => { + self.interner.set_field_index(expr_id, index); + // We must update `access` in case we added any dereferences to it + self.interner.replace_expr(&expr_id, HirExpression::MemberAccess(access)); + element_type + } + None => Type::Error, + } + } + + pub(super) fn lookup_method( + &mut self, + object_type: &Type, + method_name: &str, + span: Span, + ) -> Option { + match object_type.follow_bindings() { + Type::Struct(typ, _args) => { + let id = typ.borrow().id; + match self.interner.lookup_method(object_type, id, method_name, false) { + Some(method_id) => Some(HirMethodReference::FuncId(method_id)), + None => { + self.push_err(TypeCheckError::UnresolvedMethodCall { + method_name: method_name.to_string(), + object_type: object_type.clone(), + span, + }); + None + } + } + } + // TODO: We should allow method calls on `impl Trait`s eventually. + // For now it is fine since they are only allowed on return types. + Type::TraitAsType(..) => { + self.push_err(TypeCheckError::UnresolvedMethodCall { + method_name: method_name.to_string(), + object_type: object_type.clone(), + span, + }); + None + } + Type::NamedGeneric(_, _) => { + let func_meta = self.interner.function_meta( + &self.current_function.expect("unexpected method outside a function"), + ); + + for constraint in &func_meta.trait_constraints { + if *object_type == constraint.typ { + if let Some(the_trait) = self.interner.try_get_trait(constraint.trait_id) { + for (method_index, method) in the_trait.methods.iter().enumerate() { + if method.name.0.contents == method_name { + let trait_method = TraitMethodId { + trait_id: constraint.trait_id, + method_index, + }; + return Some(HirMethodReference::TraitMethodId( + trait_method, + constraint.trait_generics.clone(), + )); + } + } + } + } + } + + self.push_err(TypeCheckError::UnresolvedMethodCall { + method_name: method_name.to_string(), + object_type: object_type.clone(), + span, + }); + None + } + // Mutable references to another type should resolve to methods of their element type. + // This may be a struct or a primitive type. + Type::MutableReference(element) => self + .interner + .lookup_primitive_trait_method_mut(element.as_ref(), method_name) + .map(HirMethodReference::FuncId) + .or_else(|| self.lookup_method(&element, method_name, span)), + + // If we fail to resolve the object to a struct type, we have no way of type + // checking its arguments as we can't even resolve the name of the function + Type::Error => None, + + // The type variable must be unbound at this point since follow_bindings was called + Type::TypeVariable(_, TypeVariableKind::Normal) => { + self.push_err(TypeCheckError::TypeAnnotationsNeeded { span }); + None + } + + other => match self.interner.lookup_primitive_method(&other, method_name) { + Some(method_id) => Some(HirMethodReference::FuncId(method_id)), + None => { + self.push_err(TypeCheckError::UnresolvedMethodCall { + method_name: method_name.to_string(), + object_type: object_type.clone(), + span, + }); + None + } + }, + } + } + + pub(super) fn type_check_call( + &mut self, + call: &HirCallExpression, + func_type: Type, + args: Vec<(Type, ExprId, Span)>, + span: Span, + ) -> Type { + // Need to setup these flags here as `self` is borrowed mutably to type check the rest of the call expression + // These flags are later used to type check calls to unconstrained functions from constrained functions + let func_mod = self.current_function.map(|func| self.interner.function_modifiers(&func)); + let is_current_func_constrained = + func_mod.map_or(true, |func_mod| !func_mod.is_unconstrained); + + let is_unconstrained_call = self.is_unconstrained_call(call.func); + self.check_if_deprecated(call.func); + + // Check that we are not passing a mutable reference from a constrained runtime to an unconstrained runtime + if is_current_func_constrained && is_unconstrained_call { + for (typ, _, _) in args.iter() { + if matches!(&typ.follow_bindings(), Type::MutableReference(_)) { + self.push_err(TypeCheckError::ConstrainedReferenceToUnconstrained { span }); + } + } + } + + let return_type = self.bind_function_type(func_type, args, span); + + // Check that we are not passing a slice from an unconstrained runtime to a constrained runtime + if is_current_func_constrained && is_unconstrained_call { + if return_type.contains_slice() { + self.push_err(TypeCheckError::UnconstrainedSliceReturnToConstrained { span }); + } else if matches!(&return_type.follow_bindings(), Type::MutableReference(_)) { + self.push_err(TypeCheckError::UnconstrainedReferenceToConstrained { span }); + } + }; + + return_type + } + + fn check_if_deprecated(&mut self, expr: ExprId) { + if let HirExpression::Ident(HirIdent { location, id, impl_kind: _ }) = + self.interner.expression(&expr) + { + if let Some(DefinitionKind::Function(func_id)) = + self.interner.try_definition(id).map(|def| &def.kind) + { + let attributes = self.interner.function_attributes(func_id); + if let Some(note) = attributes.get_deprecated_note() { + self.push_err(TypeCheckError::CallDeprecated { + name: self.interner.definition_name(id).to_string(), + note, + span: location.span, + }); + } + } + } + } + + fn is_unconstrained_call(&self, expr: ExprId) -> bool { + if let HirExpression::Ident(HirIdent { id, .. }) = self.interner.expression(&expr) { + if let Some(DefinitionKind::Function(func_id)) = + self.interner.try_definition(id).map(|def| &def.kind) + { + let modifiers = self.interner.function_modifiers(func_id); + return modifiers.is_unconstrained; + } + } + false + } + + /// Check if the given method type requires a mutable reference to the object type, and check + /// if the given object type is already a mutable reference. If not, add one. + /// This is used to automatically transform a method call: `foo.bar()` into a function + /// call: `bar(&mut foo)`. + /// + /// A notable corner case of this function is where it interacts with auto-deref of `.`. + /// If a field is being mutated e.g. `foo.bar.mutate_bar()` where `foo: &mut Foo`, the compiler + /// will insert a dereference before bar `(*foo).bar.mutate_bar()` which would cause us to + /// mutate a copy of bar rather than a reference to it. We must check for this corner case here + /// and remove the implicitly added dereference operator if we find one. + pub(super) fn try_add_mutable_reference_to_object( + &mut self, + function_type: &Type, + object_type: &mut Type, + object: &mut ExprId, + ) { + let expected_object_type = match function_type { + Type::Function(args, _, _) => args.first(), + Type::Forall(_, typ) => match typ.as_ref() { + Type::Function(args, _, _) => args.first(), + typ => unreachable!("Unexpected type for function: {typ}"), + }, + typ => unreachable!("Unexpected type for function: {typ}"), + }; + + if let Some(expected_object_type) = expected_object_type { + let actual_type = object_type.follow_bindings(); + + if matches!(expected_object_type.follow_bindings(), Type::MutableReference(_)) { + if !matches!(actual_type, Type::MutableReference(_)) { + if let Err(error) = verify_mutable_reference(&self.interner, *object) { + self.push_err(TypeCheckError::ResolverError(error)); + } + + let new_type = Type::MutableReference(Box::new(actual_type)); + *object_type = new_type.clone(); + + // First try to remove a dereference operator that may have been implicitly + // inserted by a field access expression `foo.bar` on a mutable reference `foo`. + let new_object = self.try_remove_implicit_dereference(*object); + + // If that didn't work, then wrap the whole expression in an `&mut` + *object = new_object.unwrap_or_else(|| { + let location = self.interner.id_location(*object); + + let new_object = + self.interner.push_expr(HirExpression::Prefix(HirPrefixExpression { + operator: UnaryOp::MutableReference, + rhs: *object, + })); + self.interner.push_expr_type(new_object, new_type); + self.interner.push_expr_location(new_object, location.span, location.file); + new_object + }); + } + // Otherwise if the object type is a mutable reference and the method is not, insert as + // many dereferences as needed. + } else if matches!(actual_type, Type::MutableReference(_)) { + let (new_object, new_type) = self.insert_auto_dereferences(*object, actual_type); + *object_type = new_type; + *object = new_object; + } + } + } +} diff --git a/compiler/noirc_frontend/src/hir/resolution/import.rs b/compiler/noirc_frontend/src/hir/resolution/import.rs index 8850331f683..343113836ed 100644 --- a/compiler/noirc_frontend/src/hir/resolution/import.rs +++ b/compiler/noirc_frontend/src/hir/resolution/import.rs @@ -2,11 +2,14 @@ use noirc_errors::{CustomDiagnostic, Span}; use thiserror::Error; use crate::graph::CrateId; +use crate::hir::def_collector::dc_crate::CompilationError; use std::collections::BTreeMap; use crate::ast::{Ident, ItemVisibility, Path, PathKind}; use crate::hir::def_map::{CrateDefMap, LocalModuleId, ModuleDefId, ModuleId, PerNs}; +use super::errors::ResolverError; + #[derive(Debug, Clone)] pub struct ImportDirective { pub module_id: LocalModuleId, @@ -53,6 +56,12 @@ pub struct ResolvedImport { pub error: Option, } +impl From for CompilationError { + fn from(error: PathResolutionError) -> Self { + Self::ResolverError(ResolverError::PathResolutionError(error)) + } +} + impl<'a> From<&'a PathResolutionError> for CustomDiagnostic { fn from(error: &'a PathResolutionError) -> Self { match &error { diff --git a/compiler/noirc_frontend/src/hir/resolution/resolver.rs b/compiler/noirc_frontend/src/hir/resolution/resolver.rs index 60baaecab59..7dc307fe716 100644 --- a/compiler/noirc_frontend/src/hir/resolution/resolver.rs +++ b/compiler/noirc_frontend/src/hir/resolution/resolver.rs @@ -56,17 +56,17 @@ use crate::hir_def::{ use super::errors::{PubPosition, ResolverError}; use super::import::PathResolution; -const SELF_TYPE_NAME: &str = "Self"; +pub const SELF_TYPE_NAME: &str = "Self"; type Scope = GenericScope; type ScopeTree = GenericScopeTree; type ScopeForest = GenericScopeForest; pub struct LambdaContext { - captures: Vec, + pub captures: Vec, /// the index in the scope tree /// (sometimes being filled by ScopeTree's find method) - scope_index: usize, + pub scope_index: usize, } /// The primary jobs of the Resolver are to validate that every variable found refers to exactly 1 @@ -1345,7 +1345,7 @@ impl<'a> Resolver<'a> { range @ ForRange::Array(_) => { let for_stmt = range.into_for(for_loop.identifier, for_loop.block, for_loop.span); - self.resolve_stmt(for_stmt, for_loop.span) + self.resolve_stmt(for_stmt.kind, for_loop.span) } } } @@ -1361,7 +1361,7 @@ impl<'a> Resolver<'a> { StatementKind::Comptime(statement) => { let hir_statement = self.resolve_stmt(statement.kind, statement.span); let statement_id = self.interner.push_stmt(hir_statement); - self.interner.push_statement_location(statement_id, statement.span, self.file); + self.interner.push_stmt_location(statement_id, statement.span, self.file); HirStatement::Comptime(statement_id) } } @@ -1370,7 +1370,7 @@ impl<'a> Resolver<'a> { pub fn intern_stmt(&mut self, stmt: Statement) -> StmtId { let hir_stmt = self.resolve_stmt(stmt.kind, stmt.span); let id = self.interner.push_stmt(hir_stmt); - self.interner.push_statement_location(id, stmt.span, self.file); + self.interner.push_stmt_location(id, stmt.span, self.file); id } diff --git a/compiler/noirc_frontend/src/hir/type_check/expr.rs b/compiler/noirc_frontend/src/hir/type_check/expr.rs index 9b40c959981..48598109829 100644 --- a/compiler/noirc_frontend/src/hir/type_check/expr.rs +++ b/compiler/noirc_frontend/src/hir/type_check/expr.rs @@ -250,14 +250,14 @@ impl<'interner> TypeChecker<'interner> { } // TODO: update object_type here? - let function_call = method_call.into_function_call( + let (_, function_call) = method_call.into_function_call( &method_ref, object_type, location, self.interner, ); - self.interner.replace_expr(expr_id, function_call); + self.interner.replace_expr(expr_id, HirExpression::Call(function_call)); // Type check the new call now that it has been changed from a method call // to a function call. This way we avoid duplicating code. diff --git a/compiler/noirc_frontend/src/hir/type_check/mod.rs b/compiler/noirc_frontend/src/hir/type_check/mod.rs index 0f8131d6ebb..2e448858d9e 100644 --- a/compiler/noirc_frontend/src/hir/type_check/mod.rs +++ b/compiler/noirc_frontend/src/hir/type_check/mod.rs @@ -25,7 +25,7 @@ use crate::{ Type, TypeBindings, }; -use self::errors::Source; +pub use self::errors::Source; pub struct TypeChecker<'interner> { interner: &'interner mut NodeInterner, diff --git a/compiler/noirc_frontend/src/hir_def/expr.rs b/compiler/noirc_frontend/src/hir_def/expr.rs index bf7d9b7b4ba..8df6785e0eb 100644 --- a/compiler/noirc_frontend/src/hir_def/expr.rs +++ b/compiler/noirc_frontend/src/hir_def/expr.rs @@ -200,13 +200,15 @@ pub enum HirMethodReference { impl HirMethodCallExpression { /// Converts a method call into a function call + /// + /// Returns ((func_var_id, func_var), call_expr) pub fn into_function_call( mut self, method: &HirMethodReference, object_type: Type, location: Location, interner: &mut NodeInterner, - ) -> HirExpression { + ) -> ((ExprId, HirIdent), HirCallExpression) { let mut arguments = vec![self.object]; arguments.append(&mut self.arguments); @@ -224,10 +226,11 @@ impl HirMethodCallExpression { (id, ImplKind::TraitMethod(*method_id, constraint, false)) } }; - let func = HirExpression::Ident(HirIdent { location, id, impl_kind }); - let func = interner.push_expr(func); + let func_var = HirIdent { location, id, impl_kind }; + let func = interner.push_expr(HirExpression::Ident(func_var.clone())); interner.push_expr_location(func, location.span, location.file); - HirExpression::Call(HirCallExpression { func, arguments, location }) + let expr = HirCallExpression { func, arguments, location }; + ((func, func_var), expr) } } diff --git a/compiler/noirc_frontend/src/hir_def/types.rs b/compiler/noirc_frontend/src/hir_def/types.rs index f3b2a24c1f0..f31aeea0552 100644 --- a/compiler/noirc_frontend/src/hir_def/types.rs +++ b/compiler/noirc_frontend/src/hir_def/types.rs @@ -1423,14 +1423,14 @@ impl Type { /// Retrieves the type of the given field name /// Panics if the type is not a struct or tuple. - pub fn get_field_type(&self, field_name: &str) -> Type { + pub fn get_field_type(&self, field_name: &str) -> Option { match self { - Type::Struct(def, args) => def.borrow().get_field(field_name, args).unwrap().0, + Type::Struct(def, args) => def.borrow().get_field(field_name, args).map(|(typ, _)| typ), Type::Tuple(fields) => { let mut fields = fields.iter().enumerate(); - fields.find(|(i, _)| i.to_string() == *field_name).unwrap().1.clone() + fields.find(|(i, _)| i.to_string() == *field_name).map(|(_, typ)| typ).cloned() } - other => panic!("Tried to iterate over the fields of '{other}', which has none"), + _ => None, } } diff --git a/compiler/noirc_frontend/src/lib.rs b/compiler/noirc_frontend/src/lib.rs index 958a18ac2fb..b05c635f436 100644 --- a/compiler/noirc_frontend/src/lib.rs +++ b/compiler/noirc_frontend/src/lib.rs @@ -12,6 +12,7 @@ pub mod ast; pub mod debug; +pub mod elaborator; pub mod graph; pub mod lexer; pub mod monomorphization; diff --git a/compiler/noirc_frontend/src/node_interner.rs b/compiler/noirc_frontend/src/node_interner.rs index 88adc7a9414..faf89016f96 100644 --- a/compiler/noirc_frontend/src/node_interner.rs +++ b/compiler/noirc_frontend/src/node_interner.rs @@ -532,7 +532,7 @@ impl NodeInterner { self.id_to_type.insert(expr_id.into(), typ); } - /// Store the type for an interned expression + /// Store the type for a definition pub fn push_definition_type(&mut self, definition_id: DefinitionId, typ: Type) { self.definition_to_type.insert(definition_id, typ); } @@ -696,7 +696,7 @@ impl NodeInterner { let statement = self.push_stmt(HirStatement::Error); let span = name.span(); let id = self.push_global(name, local_id, statement, file, attributes, mutable); - self.push_statement_location(statement, span, file); + self.push_stmt_location(statement, span, file); id } @@ -942,7 +942,7 @@ impl NodeInterner { self.id_location(stmt_id) } - pub fn push_statement_location(&mut self, id: StmtId, span: Span, file: FileId) { + pub fn push_stmt_location(&mut self, id: StmtId, span: Span, file: FileId) { self.id_to_location.insert(id.into(), Location::new(span, file)); }