feat(traits): Implement trait bounds def collector + resolver passes

compiler/noirc_frontend/src/ast/expression.rs

@@ -3,8 +3,8 @@ use std::fmt::Display;
 
 use crate::token::{Attributes, Token};
 use crate::{
-    Distinctness, Ident, Path, Pattern, Recoverable, Statement, TraitConstraint, UnresolvedType,
-    UnresolvedTypeData, Visibility,
+    Distinctness, Ident, Path, Pattern, Recoverable, Statement, UnresolvedTraitConstraint,
+    UnresolvedType, UnresolvedTypeData, Visibility,
 };
 use acvm::FieldElement;
 use iter_extended::vecmap;
@@ -368,7 +368,7 @@ pub struct FunctionDefinition {
     pub parameters: Vec<(Pattern, UnresolvedType, Visibility)>,
     pub body: BlockExpression,
     pub span: Span,
-    pub where_clause: Vec<TraitConstraint>,
+    pub where_clause: Vec<UnresolvedTraitConstraint>,
     pub return_type: FunctionReturnType,
     pub return_visibility: Visibility,
     pub return_distinctness: Distinctness,
@@ -634,7 +634,7 @@ impl FunctionDefinition {
         generics: &UnresolvedGenerics,
         parameters: &[(Ident, UnresolvedType)],
         body: &BlockExpression,
-        where_clause: &[TraitConstraint],
+        where_clause: &[UnresolvedTraitConstraint],
         return_type: &FunctionReturnType,
     ) -> FunctionDefinition {
         let p = parameters

compiler/noirc_frontend/src/ast/traits.rs

@@ -4,8 +4,8 @@ use iter_extended::vecmap;
 use noirc_errors::Span;
 
 use crate::{
-    BlockExpression, Expression, FunctionReturnType, Ident, NoirFunction, UnresolvedGenerics,
-    UnresolvedType,
+    node_interner::TraitId, BlockExpression, Expression, FunctionReturnType, Ident, NoirFunction,
+    UnresolvedGenerics, UnresolvedType,
 };
 
 /// AST node for trait definitions:
@@ -14,7 +14,7 @@ use crate::{
 pub struct NoirTrait {
     pub name: Ident,
     pub generics: Vec<Ident>,
-    pub where_clause: Vec<TraitConstraint>,
+    pub where_clause: Vec<UnresolvedTraitConstraint>,
     pub span: Span,
     pub items: Vec<TraitItem>,
 }
@@ -28,7 +28,7 @@ pub enum TraitItem {
         generics: Vec<Ident>,
         parameters: Vec<(Ident, UnresolvedType)>,
         return_type: FunctionReturnType,
-        where_clause: Vec<TraitConstraint>,
+        where_clause: Vec<UnresolvedTraitConstraint>,
         body: Option<BlockExpression>,
     },
     Constant {
@@ -54,7 +54,7 @@ pub struct TypeImpl {
 /// Ast node for an implementation of a trait for a particular type
 /// `impl trait_name<trait_generics> for object_type where where_clauses { ... items ... }`
 #[derive(Clone, Debug)]
-pub struct TraitImpl {
+pub struct NoirTraitImpl {
     pub impl_generics: UnresolvedGenerics,
 
     pub trait_name: Ident,
@@ -63,7 +63,7 @@ pub struct TraitImpl {
     pub object_type: UnresolvedType,
     pub object_type_span: Span,
 
-    pub where_clause: Vec<TraitConstraint>,
+    pub where_clause: Vec<UnresolvedTraitConstraint>,
 
     pub items: Vec<TraitImplItem>,
 }
@@ -75,7 +75,7 @@ pub struct TraitImpl {
 ///   `Foo: TraitX`
 ///   `Foo: TraitY<U, V>`
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub struct TraitConstraint {
+pub struct UnresolvedTraitConstraint {
     pub typ: UnresolvedType,
     pub trait_bound: TraitBound,
 }
@@ -84,6 +84,7 @@ pub struct TraitConstraint {
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct TraitBound {
     pub trait_name: Ident,
+    pub trait_id: Option<TraitId>, // initially None, gets assigned during DC
     pub trait_generics: Vec<UnresolvedType>,
 }
 
@@ -167,7 +168,7 @@ impl Display for TraitItem {
     }
 }
 
-impl Display for TraitConstraint {
+impl Display for UnresolvedTraitConstraint {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "{}: {}", self.typ, self.trait_bound)
     }
@@ -184,7 +185,7 @@ impl Display for TraitBound {
     }
 }
 
-impl Display for TraitImpl {
+impl Display for NoirTraitImpl {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let generics = vecmap(&self.trait_generics, |generic| generic.to_string());
         let generics = generics.join(", ");

compiler/noirc_frontend/src/hir/def_collector/dc_crate.rs

@@ -11,8 +11,10 @@
 };
 use crate::hir::type_check::{type_check_func, TypeCheckError, TypeChecker};
 use crate::hir::Context;
-use crate::hir_def::traits::{TraitConstant, TraitFunction, TraitType};
-use crate::node_interner::{FuncId, NodeInterner, StmtId, StructId, TraitId, TypeAliasId};
+use crate::hir_def::traits::{TraitConstant, TraitFunction, TraitImpl, TraitType};
+use crate::node_interner::{
+    FuncId, NodeInterner, StmtId, StructId, TraitId, TraitImplKey, TypeAliasId,
+};
 use crate::{
     ExpressionKind, Generics, Ident, LetStatement, Literal, NoirFunction, NoirStruct, NoirTrait,
     NoirTypeAlias, ParsedModule, Shared, StructType, TraitItem, Type, TypeBinding,
@@ -696,24 +698,31 @@
             errors,
         );
 
+        let resolved_trait_impl = Shared::new(TraitImpl {
+            ident: trait_impl.trait_impl_ident.clone(),
+            typ: self_type.clone(),
+            trait_id,
+            methods: vecmap(&impl_methods, |(_, func_id)| *func_id),
+        });
+
         let mut new_resolver =
             Resolver::new(interner, &path_resolver, &context.def_maps, trait_impl.file_id);
         new_resolver.set_self_type(Some(self_type.clone()));
 
         check_methods_signatures(&mut new_resolver, &impl_methods, trait_id, errors);
 
         let trait_definition_ident = &trait_impl.trait_impl_ident;
-        let key = (self_type.clone(), trait_id);
-        if let Some(prev_trait_impl_ident) = interner.get_previous_trait_implementation(&key) {
+        let key = TraitImplKey { typ: self_type.clone(), trait_id };
+
+        if let Some(prev_trait_impl_ident) = interner.get_trait_implementation(&key) {
             let err = DefCollectorErrorKind::Duplicate {
                 typ: DuplicateType::TraitImplementation,
-                first_def: prev_trait_impl_ident.clone(),
+                first_def: prev_trait_impl_ident.borrow().ident.clone(),
                 second_def: trait_definition_ident.clone(),
             };
             errors.push(err.into_file_diagnostic(trait_impl.methods.file_id));
         } else {
-            let _func_ids =
-                interner.add_trait_implementaion(&key, trait_definition_ident, &trait_impl.methods);
+            interner.add_trait_implementation(&key, resolved_trait_impl.clone());
         }
 
         methods.append(&mut impl_methods);
@@ -722,7 +731,7 @@
     methods
 }
 
 // TODO(vitkov): Move this out of here and into type_check
 fn check_methods_signatures(
     resolver: &mut Resolver,
     impl_methods: &Vec<(FileId, FuncId)>,
@@ -741,7 +750,7 @@
         let meta = resolver.interner.function_meta(func_id);
         let func_name = resolver.interner.function_name(func_id).to_owned();
 
         let mut typecheck_errors = Vec::new();
 
         // `method` is None in the case where the impl block has a method that's not part of the trait.
         // If that's the case, a `MethodNotInTrait` error has already been thrown, and we can ignore
@@ -757,7 +766,7 @@
                     for (parameter_index, ((expected, actual), (hir_pattern, _, _))) in
                         method.arguments.iter().zip(&params).zip(&meta.parameters.0).enumerate()
                     {
                         expected.unify(actual, &mut typecheck_errors, || {
                             TypeCheckError::TraitMethodParameterTypeMismatch {
                                 method_name: func_name.to_string(),
                                 expected_typ: expected.to_string(),
@@ -785,7 +794,7 @@
             let resolved_return_type =
                 resolver.resolve_type(meta.return_type.get_type().into_owned());
 
             method.return_type.unify(&resolved_return_type, &mut typecheck_errors, || {
                 let ret_type_span =
                     meta.return_type.get_type().span.expect("return type must always have a span");
 
@@ -796,7 +805,7 @@
                 }
             });
 
             extend_errors(errors, *file_id, typecheck_errors);
         }
     }
 

compiler/noirc_frontend/src/hir/def_collector/dc_mod.rs

@@ -5,11 +5,14 @@
 
 use crate::{
     graph::CrateId,
-    hir::def_collector::dc_crate::{UnresolvedStruct, UnresolvedTrait},
+    hir::{
+        def_collector::dc_crate::{UnresolvedStruct, UnresolvedTrait},
+        def_map::ScopeResolveError,
+    },
     node_interner::TraitId,
     parser::SubModule,
-    FunctionDefinition, Ident, LetStatement, NoirFunction, NoirStruct, NoirTrait, NoirTypeAlias,
-    ParsedModule, TraitImpl, TraitImplItem, TraitItem, TypeImpl,
+    FunctionDefinition, Ident, LetStatement, NoirFunction, NoirStruct, NoirTrait, NoirTraitImpl,
+    NoirTypeAlias, ParsedModule, TraitImplItem, TraitItem, TypeImpl,
 };
 
 use super::{
@@ -19,7 +22,7 @@
     },
     errors::{DefCollectorErrorKind, DuplicateType},
 };
-use crate::hir::def_map::{parse_file, LocalModuleId, ModuleData, ModuleDefId, ModuleId};
+use crate::hir::def_map::{parse_file, LocalModuleId, ModuleData, ModuleId};
 use crate::hir::resolution::import::ImportDirective;
 use crate::hir::Context;
 
@@ -131,73 +134,71 @@
     fn collect_trait_impls(
         &mut self,
         context: &mut Context,
-        impls: Vec<TraitImpl>,
+        impls: Vec<NoirTraitImpl>,
         errors: &mut Vec<FileDiagnostic>,
     ) {
         for trait_impl in impls {
-            let trait_name = trait_impl.trait_name.clone();
+            let trait_name = &trait_impl.trait_name;
             let module = &self.def_collector.def_map.modules[self.module_id.0];
-            match module.find_name(&trait_name).types {
-                Some((module_def_id, _visibility)) => {
-                    if let Some(collected_trait) = self.get_unresolved_trait(module_def_id) {
-                        let unresolved_functions = self.collect_trait_implementations(
-                            context,
-                            &trait_impl,
-                            &collected_trait.trait_def,
-                            errors,
-                        );
-
-                        for (_, func_id, noir_function) in &unresolved_functions.functions {
-                            let name = noir_function.name().to_owned();
-
-                            context.def_interner.push_function_definition(name, *func_id);
-                        }
 
-                        let unresolved_trait_impl = UnresolvedTraitImpl {
-                            file_id: self.file_id,
-                            module_id: self.module_id,
-                            the_trait: collected_trait,
-                            methods: unresolved_functions,
-                            trait_impl_ident: trait_impl.trait_name.clone(),
-                        };
-
-                        let trait_id = match module_def_id {
-                            ModuleDefId::TraitId(trait_id) => trait_id,
-                            _ => unreachable!(),
-                        };
-
-                        let key = (trait_impl.object_type, self.module_id, trait_id);
-                        self.def_collector
-                            .collected_traits_impls
-                            .insert(key, unresolved_trait_impl);
-                    } else {
-                        let error = DefCollectorErrorKind::NotATrait {
-                            not_a_trait_name: trait_name.clone(),
-                        };
-                        errors.push(error.into_file_diagnostic(self.file_id));
-                    }
-                }
-                None => {
-                    let error = DefCollectorErrorKind::TraitNotFound { trait_ident: trait_name };
-                    errors.push(error.into_file_diagnostic(self.file_id));
+            if let Some(trait_id) = self.find_trait_or_emit_error(module, trait_name, errors) {
+                let collected_trait =
+                    self.def_collector.collected_traits.get(&trait_id).cloned().unwrap();
+
+                let unresolved_functions = self.collect_trait_implementations(
+                    context,
+                    &trait_impl,
+                    &collected_trait.trait_def,
+                    errors,
+                );
+
+                for (_, func_id, noir_function) in &unresolved_functions.functions {
+                    let name = noir_function.name().to_owned();
+
+                    context.def_interner.push_function_definition(name, *func_id);
                 }
+
+                let unresolved_trait_impl = UnresolvedTraitImpl {
+                    file_id: self.file_id,
+                    module_id: self.module_id,
+                    the_trait: collected_trait,
+                    methods: unresolved_functions,
+                    trait_impl_ident: trait_impl.trait_name.clone(),
+                };
+
+                let key = (trait_impl.object_type, self.module_id, trait_id);
+                self.def_collector.collected_traits_impls.insert(key, unresolved_trait_impl);
             }
         }
     }
 
-    fn get_unresolved_trait(&self, module_def_id: ModuleDefId) -> Option<UnresolvedTrait> {
-        match module_def_id {
-            ModuleDefId::TraitId(trait_id) => {
-                self.def_collector.collected_traits.get(&trait_id).cloned()
+    fn find_trait_or_emit_error(
+        &self,
+        module: &ModuleData,
+        trait_name: &Ident,
+        errors: &mut Vec<FileDiagnostic>,
+    ) -> Option<TraitId> {
+        match module.find_trait_with_name(trait_name) {
+            Ok(trait_id) => Some(trait_id),
+            Err(ScopeResolveError::WrongKind) => {
+                let error =
+                    DefCollectorErrorKind::NotATrait { not_a_trait_name: trait_name.clone() };
+                errors.push(error.into_file_diagnostic(self.file_id));
+                None
+            }
+            Err(ScopeResolveError::NotFound) => {
+                let error =
+                    DefCollectorErrorKind::TraitNotFound { trait_ident: trait_name.clone() };
+                errors.push(error.into_file_diagnostic(self.file_id));
+                None
             }
-            _ => None,
         }
     }
 
     fn collect_trait_implementations(
         &mut self,
         context: &mut Context,
-        trait_impl: &TraitImpl,
+        trait_impl: &NoirTraitImpl,
         trait_def: &NoirTrait,
         errors: &mut Vec<FileDiagnostic>,
     ) -> UnresolvedFunctions {
@@ -218,7 +219,7 @@
         let mut func_ids_in_trait = HashSet::new();
 
         for item in &trait_def.items {
             // TODO(Maddiaa): Investigate trait implementations with attributes see: https://github.com/noir-lang/noir/issues/2629
             if let TraitItem::Function {
                 name,
                 generics,
@@ -296,14 +297,27 @@
         let mut unresolved_functions =
             UnresolvedFunctions { file_id: self.file_id, functions: Vec::new() };
 
-        for function in functions {
+        for mut function in functions {
             let name = function.name_ident().clone();
 
             // First create dummy function in the DefInterner
             // So that we can get a FuncId
             let func_id = context.def_interner.push_empty_fn();
             context.def_interner.push_function_definition(name.0.contents.clone(), func_id);
 
+            // Then go over the where clause and assign trait_ids to the constraints
+            for constraint in &mut function.def.where_clause {
+                let module = &self.def_collector.def_map.modules[self.module_id.0];
+
+                if let Some(trait_id) = self.find_trait_or_emit_error(
+                    module,
+                    &constraint.trait_bound.trait_name,
+                    errors,
+                ) {
+                    constraint.trait_bound.trait_id = Some(trait_id);
+                }
+            }
+
             // Now link this func_id to a crate level map with the noir function and the module id
             // Encountering a NoirFunction, we retrieve it's module_data to get the namespace
             // Once we have lowered it to a HirFunction, we retrieve it's Id from the DefInterner

compiler/noirc_frontend/src/hir/def_map/item_scope.rs

@@ -1,5 +1,8 @@
 use super::{namespace::PerNs, ModuleDefId, ModuleId};
-use crate::{node_interner::FuncId, Ident};
+use crate::{
+    node_interner::{FuncId, TraitId},
+    Ident,
+};
 use std::collections::{hash_map::Entry, HashMap};
 
 #[derive(Debug, PartialEq, Eq, Copy, Clone)]
@@ -15,6 +18,14 @@ pub struct ItemScope {
     defs: Vec<ModuleDefId>,
 }
 
+pub enum ScopeResolveError {
+    /// the ident we attempted to resolve isn't declared
+    NotFound,
+
+    /// The ident we attempted to resolve is declared, but is the wrong kind - e.g. we want a trait, but it's a function
+    WrongKind,
+}
+
 impl ItemScope {
     pub fn add_definition(
         &mut self,
@@ -69,6 +80,14 @@ impl ItemScope {
             _ => None,
         }
     }
+    pub fn find_trait_with_name(&self, trait_name: &Ident) -> Result<TraitId, ScopeResolveError> {
+        let (module_def, _) = self.types.get(trait_name).ok_or(ScopeResolveError::NotFound)?;
+
+        match module_def {
+            ModuleDefId::TraitId(id) => Ok(*id),
+            _ => Err(ScopeResolveError::WrongKind),
+        }
+    }
 
     pub fn find_name(&self, name: &Ident) -> PerNs {
         PerNs { types: self.types.get(name).cloned(), values: self.values.get(name).cloned() }

compiler/noirc_frontend/src/hir/def_map/module_data.rs

@@ -7,7 +7,7 @@ use crate::{
     Ident,
 };
 
-use super::{ItemScope, LocalModuleId, ModuleDefId, ModuleId, PerNs};
+use super::{ItemScope, LocalModuleId, ModuleDefId, ModuleId, PerNs, ScopeResolveError};
 
 /// Contains the actual contents of a module: its parent (if one exists),
 /// children, and scope with all definitions defined within the scope.
@@ -85,6 +85,10 @@ impl ModuleData {
         self.scope.find_func_with_name(name)
     }
 
+    pub fn find_trait_with_name(&self, name: &Ident) -> Result<TraitId, ScopeResolveError> {
+        self.scope.find_trait_with_name(name)
+    }
+
     pub fn import(&mut self, name: Ident, id: ModuleDefId) -> Result<(), (Ident, Ident)> {
         self.scope.add_item_to_namespace(name, id)
     }