fix: Derive generic types

aztec_macros/src/utils/parse_utils.rs

@@ -349,6 +349,7 @@
             empty_ident(ident);
             empty_unresolved_type(typ);
         }
+        UnresolvedGeneric::Resolved(..) => (),
     }
 }
 
@@ -374,9 +375,9 @@
 }
 
 fn empty_unresolved_trait_constraints(
     unresolved_trait_constriants: &mut [UnresolvedTraitConstraint],
 ) {
     for trait_constraint in unresolved_trait_constriants.iter_mut() {
         empty_unresolved_trait_constraint(trait_constraint);
     }
 }

compiler/noirc_frontend/src/ast/expression.rs

@@ -7,7 +7,7 @@ use crate::ast::{
 };
 use crate::hir::def_collector::errors::DefCollectorErrorKind;
 use crate::macros_api::StructId;
-use crate::node_interner::ExprId;
+use crate::node_interner::{ExprId, QuotedTypeId};
 use crate::token::{Attributes, Token, Tokens};
 use crate::{Kind, Type};
 use acvm::{acir::AcirField, FieldElement};
@@ -51,7 +51,16 @@ pub type UnresolvedGenerics = Vec<UnresolvedGeneric>;
 #[derive(Debug, PartialEq, Eq, Clone, Hash)]
 pub enum UnresolvedGeneric {
     Variable(Ident),
-    Numeric { ident: Ident, typ: UnresolvedType },
+    Numeric {
+        ident: Ident,
+        typ: UnresolvedType,
+    },
+
+    /// Already-resolved generics can be parsed as generics when a macro
+    /// splices existing types into a generic list. In this case we have
+    /// to validate the type refers to a named generic and treat that
+    /// as a ResolvedGeneric when this is resolved.
+    Resolved(QuotedTypeId, Span),
 }
 
 impl UnresolvedGeneric {
@@ -61,6 +70,7 @@ impl UnresolvedGeneric {
             UnresolvedGeneric::Numeric { ident, typ } => {
                 ident.0.span().merge(typ.span.unwrap_or_default())
             }
+            UnresolvedGeneric::Resolved(_, span) => *span,
         }
     }
 
@@ -71,6 +81,9 @@ impl UnresolvedGeneric {
                 let typ = self.resolve_numeric_kind_type(typ)?;
                 Ok(Kind::Numeric(Box::new(typ)))
             }
+            UnresolvedGeneric::Resolved(..) => {
+                panic!("Don't know the kind of a resolved generic here")
+            }
         }
     }
 
@@ -94,6 +107,7 @@ impl UnresolvedGeneric {
     pub(crate) fn ident(&self) -> &Ident {
         match self {
             UnresolvedGeneric::Variable(ident) | UnresolvedGeneric::Numeric { ident, .. } => ident,
+            UnresolvedGeneric::Resolved(..) => panic!("UnresolvedGeneric::Resolved no ident"),
         }
     }
 }
@@ -103,6 +117,7 @@ impl Display for UnresolvedGeneric {
         match self {
             UnresolvedGeneric::Variable(ident) => write!(f, "{ident}"),
             UnresolvedGeneric::Numeric { ident, typ } => write!(f, "let {ident}: {typ}"),
+            UnresolvedGeneric::Resolved(..) => write!(f, "(resolved)"),
         }
     }
 }

compiler/noirc_frontend/src/elaborator/mod.rs

@@ -502,35 +502,72 @@ impl<'context> Elaborator<'context> {
     /// Each generic will have a fresh Shared<TypeBinding> associated with it.
     pub fn add_generics(&mut self, generics: &UnresolvedGenerics) -> Generics {
         vecmap(generics, |generic| {
-            // Map the generic to a fresh type variable
-            let id = self.interner.next_type_variable_id();
-            let typevar = TypeVariable::unbound(id);
-            let ident = generic.ident();
-            let span = ident.0.span();
+            let mut is_error = false;
+            let (type_var, name, kind) = match self.resolve_generic(generic) {
+                Ok(values) => values,
+                Err(error) => {
+                    self.push_err(error);
+                    is_error = true;
+                    let id = self.interner.next_type_variable_id();
+                    (TypeVariable::unbound(id), Rc::new("(error)".into()), Kind::Normal)
+                }
+            };
 
-            // Resolve the generic's kind
-            let kind = self.resolve_generic_kind(generic);
+            let span = generic.span();
+            let name_owned = name.as_ref().clone();
+            let resolved_generic = ResolvedGeneric { name, type_var, kind, span };
 
             // Check for name collisions of this generic
-            let name = Rc::new(ident.0.contents.clone());
-
-            let resolved_generic =
-                ResolvedGeneric { name: name.clone(), type_var: typevar.clone(), kind, span };
-
-            if let Some(generic) = self.find_generic(&name) {
-                self.push_err(ResolverError::DuplicateDefinition {
-                    name: ident.0.contents.clone(),
-                    first_span: generic.span,
-                    second_span: span,
-                });
-            } else {
-                self.generics.push(resolved_generic.clone());
+            // Checking `is_error` here prevents DuplicateDefinition errors when
+            // we have multiple generics from macros which fail to resolve and
+            // are all given the same default name "(error)".
+            if !is_error {
+                if let Some(generic) = self.find_generic(&name_owned) {
+                    self.push_err(ResolverError::DuplicateDefinition {
+                        name: name_owned,
+                        first_span: generic.span,
+                        second_span: span,
+                    });
+                } else {
+                    self.generics.push(resolved_generic.clone());
+                }
             }
 
             resolved_generic
         })
     }
 
+    fn resolve_generic(
+        &mut self,
+        generic: &UnresolvedGeneric,
+    ) -> Result<(TypeVariable, Rc<String>, Kind), ResolverError> {
+        // Map the generic to a fresh type variable
+        match generic {
+            UnresolvedGeneric::Variable(_) | UnresolvedGeneric::Numeric { .. } => {
+                let id = self.interner.next_type_variable_id();
+                let typevar = TypeVariable::unbound(id);
+                let ident = generic.ident();
+
+                let kind = self.resolve_generic_kind(generic);
+                let name = Rc::new(ident.0.contents.clone());
+                Ok((typevar, name, kind))
+            }
+            // An already-resolved generic is only possible if it is the result of a
+            // previous macro call being inserted into a generics list.
+            UnresolvedGeneric::Resolved(id, span) => {
+                match self.interner.get_quoted_type(*id).follow_bindings() {
+                    Type::NamedGeneric(type_variable, name, kind) => {
+                        Ok((type_variable, name, kind))
+                    }
+                    other => Err(ResolverError::MacroResultInGenericsListNotAGeneric {
+                        span: *span,
+                        typ: other.clone(),
+                    }),
+                }
+            }
+        }
+    }
+
     /// Return the kind of an unresolved generic.
     /// If a numeric generic has been specified, resolve the annotated type to make
     /// sure only primitive numeric types are being used.
@@ -1300,6 +1337,11 @@ impl<'context> Elaborator<'context> {
             self.add_generics(&trait_impl.generics);
             trait_impl.resolved_generics = self.generics.clone();
 
+            for (_, _, method) in trait_impl.methods.functions.iter_mut() {
+                // Attach any trait constraints on the impl to the function
+                method.def.where_clause.append(&mut trait_impl.where_clause.clone());
+            }
+
             // Fetch trait constraints here
             let trait_generics = trait_impl
                 .trait_id

compiler/noirc_frontend/src/hir/comptime/interpreter/builtin.rs

@@ -249,7 +249,7 @@
     Ok(Value::Type(Type::Struct(struct_def_rc, generics)))
 }
 
-/// fn generics(self) -> [Quoted]
+/// fn generics(self) -> [Type]
 fn struct_def_generics(
     interner: &NodeInterner,
     mut arguments: Vec<(Value, Location)>,
@@ -269,12 +269,10 @@
     let struct_def = interner.get_struct(struct_def);
     let struct_def = struct_def.borrow();
 
-    let generics = struct_def.generics.iter().map(|generic| {
-        let name = Token::Ident(generic.type_var.borrow().to_string());
-        Value::Quoted(Rc::new(vec![name]))
-    });
+    let generics =
+        struct_def.generics.iter().map(|generic| Value::Type(generic.clone().as_named_generic()));
 
-    let typ = Type::Slice(Box::new(Type::Quoted(QuotedType::Quoted)));
+    let typ = Type::Slice(Box::new(Type::Quoted(QuotedType::Type)));
     Ok(Value::Slice(generics.collect(), typ))
 }
 
@@ -439,7 +437,7 @@
     })?;
 
     let typ =
         interpreter.elaborate_item(interpreter.current_function, |elab| elab.resolve_type(typ));
 
     Ok(Value::Type(typ))
 }

compiler/noirc_frontend/src/hir/comptime/value.rs

@@ -497,7 +497,12 @@ impl<'value, 'interner> Display for ValuePrinter<'value, 'interner> {
             Value::Quoted(tokens) => {
                 write!(f, "quote {{")?;
                 for token in tokens.iter() {
-                    write!(f, " {token}")?;
+                    match token {
+                        Token::QuotedType(id) => {
+                            write!(f, " {:?}", self.interner.get_quoted_type(*id))?;
+                        }
+                        other => write!(f, " {other}")?,
+                    }
                 }
                 write!(f, " }}")
             }

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

@@ -173,8 +173,6 @@ impl<'a> ModCollector<'a> {
             let module = ModuleId { krate, local_id: self.module_id };
 
             for (_, func_id, noir_function) in &mut unresolved_functions.functions {
-                // Attach any trait constraints on the impl to the function
-                noir_function.def.where_clause.append(&mut trait_impl.where_clause.clone());
                 let location = Location::new(noir_function.def.span, self.file_id);
                 context.def_interner.push_function(*func_id, &noir_function.def, module, location);
             }

compiler/noirc_frontend/src/hir/resolution/errors.rs

@@ -114,6 +114,8 @@ pub enum ResolverError {
     MacroIsNotComptime { span: Span },
     #[error("Annotation name must refer to a comptime function")]
     NonFunctionInAnnotation { span: Span },
+    #[error("Type `{typ}` was inserted into the generics list from a macro, but is not a generic")]
+    MacroResultInGenericsListNotAGeneric { span: Span, typ: Type },
 }
 
 impl ResolverError {
@@ -458,6 +460,13 @@ impl<'a> From<&'a ResolverError> for Diagnostic {
                     *span,
                 )
             },
+            ResolverError::MacroResultInGenericsListNotAGeneric { span, typ } => {
+                Diagnostic::simple_error(
+                    format!("Type `{typ}` was inserted into a generics list from a macro, but it is not a generic"),
+                    format!("Type `{typ}` is not a generic"),
+                    *span,
+                )
+            }
         }
     }
 }

compiler/noirc_frontend/src/hir_def/types.rs

@@ -191,6 +191,12 @@
     pub span: Span,
 }
 
+impl ResolvedGeneric {
+    pub fn as_named_generic(self) -> Type {
+        Type::NamedGeneric(self.type_var, self.name, self.kind)
+    }
+}
+
 impl std::hash::Hash for StructType {
     fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
         self.id.hash(state);
@@ -1801,7 +1807,7 @@
         }
 
         let recur_on_binding = |id, replacement: &Type| {
             // Prevent recuring forever if there's a `T := T` binding
             if replacement.type_variable_id() == Some(id) {
                 replacement.clone()
             } else {
@@ -1872,7 +1878,7 @@
                 Type::Tuple(fields)
             }
             Type::Forall(typevars, typ) => {
                 // Trying to substitute_helper a variable de, substitute_bound_typevarsfined within a nested Forall
                 // is usually impossible and indicative of an error in the type checker somewhere.
                 for var in typevars {
                     assert!(!type_bindings.contains_key(&var.id()));
@@ -2018,7 +2024,7 @@
 
     /// Replace any `Type::NamedGeneric` in this type with a `Type::TypeVariable`
     /// using to the same inner `TypeVariable`. This is used during monomorphization
     /// to bind to named generics since they are unbindable during type checking.
     pub fn replace_named_generics_with_type_variables(&mut self) {
         match self {
             Type::FieldElement

compiler/noirc_frontend/src/parser/parser/function.rs

@@ -2,9 +2,10 @@ use super::{
     attributes::{attributes, validate_attributes},
     block, fresh_statement, ident, keyword, maybe_comp_time, nothing, optional_visibility,
     parameter_name_recovery, parameter_recovery, parenthesized, parse_type, pattern,
+    primitives::token_kind,
     self_parameter, where_clause, NoirParser,
 };
-use crate::token::{Keyword, Token};
+use crate::token::{Keyword, Token, TokenKind};
 use crate::{ast::IntegerBitSize, parser::spanned};
 use crate::{
     ast::{
@@ -110,8 +111,15 @@ pub(super) fn generic_type() -> impl NoirParser<UnresolvedGeneric> {
     ident().map(UnresolvedGeneric::Variable)
 }
 
+pub(super) fn resolved_generic() -> impl NoirParser<UnresolvedGeneric> {
+    token_kind(TokenKind::QuotedType).map_with_span(|token, span| match token {
+        Token::QuotedType(id) => UnresolvedGeneric::Resolved(id, span),
+        _ => unreachable!("token_kind(QuotedType) guarantees we parse a quoted type"),
+    })
+}
+
 pub(super) fn generic() -> impl NoirParser<UnresolvedGeneric> {
-    generic_type().or(numeric_generic())
+    generic_type().or(numeric_generic()).or(resolved_generic())
 }
 
 /// non_empty_ident_list: ident ',' non_empty_ident_list

compiler/noirc_frontend/src/parser/parser/types.rs

@@ -133,7 +133,7 @@ fn quoted_type() -> impl NoirParser<UnresolvedType> {
 /// This is the type of an already resolved type.
 /// The only way this can appear in the token input is if an already resolved `Type` object
 /// was spliced into a macro's token stream via the `$` operator.
-fn resolved_type() -> impl NoirParser<UnresolvedType> {
+pub(super) fn resolved_type() -> impl NoirParser<UnresolvedType> {
     token_kind(TokenKind::QuotedType).map_with_span(|token, span| match token {
         Token::QuotedType(id) => UnresolvedTypeData::Resolved(id).with_span(span),
         _ => unreachable!("token_kind(QuotedType) guarantees we parse a quoted type"),

noir_stdlib/src/cmp.nr

@@ -10,9 +10,9 @@ trait Eq {
 comptime fn derive_eq(s: StructDefinition) -> Quoted {
     let typ = s.as_type();
 
-    let impl_generics = s.generics().join(quote {,});
+    let impl_generics = s.generics().map(|g| quote { $g }).join(quote {,});
 
-    let where_clause = s.generics().map(|name| quote { $name: Default }).join(quote {,});
+    let where_clause = s.generics().map(|name| quote { $name: Eq }).join(quote {,});
 
     // `(self.a == other.a) & (self.b == other.b) & ...`
     let equalities = s.fields().map(

noir_stdlib/src/default.nr

@@ -10,7 +10,7 @@ trait Default {
 comptime fn derive_default(s: StructDefinition) -> Quoted {
     let typ = s.as_type();
 
-    let impl_generics = s.generics().join(quote {,});
+    let impl_generics = s.generics().map(|g| quote { $g }).join(quote {,});
 
     let where_clause = s.generics().map(|name| quote { $name: Default }).join(quote {,});
 

noir_stdlib/src/meta/struct_def.nr

@@ -4,10 +4,9 @@ impl StructDefinition {
     #[builtin(struct_def_as_type)]
     fn as_type(self) -> Type {}
 
-    /// Return each generic on this struct. The names of these generics are unchanged
-    /// so users may need to keep name collisions in mind if this is used directly in a macro.
+    /// Return each generic on this struct.
     #[builtin(struct_def_generics)]
-    fn generics(self) -> [Quoted] {}
+    fn generics(self) -> [Type] {}
 
     /// Returns (name, type) pairs of each field in this struct. Each type is as-is
     /// with any generic arguments unchanged.

test_programs/compile_success_empty/derive_impl/src/main.nr

@@ -1,5 +1,5 @@
 comptime fn derive_default(typ: StructDefinition) -> Quoted {
-    let generics: [Quoted] = typ.generics();
+    let generics = typ.generics();
     assert_eq(
         generics.len(), 0, "derive_default: Deriving Default on generic types is currently unimplemented"
     );

test_programs/compile_success_empty/regression_5671/Nargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "regression_5671"
+type = "bin"
+authors = [""]
+compiler_version = ">=0.32.0"
+
+[dependencies]

test_programs/compile_success_empty/regression_5671/src/main.nr

@@ -0,0 +1,20 @@
+#[foo]
+struct MyOtherStruct<A, B> {
+    field1: A,
+    field2: B,
+}
+
+comptime fn foo(_s: StructDefinition) -> Quoted {
+    quote {
+        impl<A, B> Eq for MyOtherStruct<A, B> where A: Eq, B: Eq {
+            fn eq(self, other: Self) -> bool {
+                (self.field1 == other.field1) & (self.field2 == other.field2)
+            }
+        }
+    }
+}
+
+fn main() {
+    let x = MyOtherStruct { field1: 1, field2: 2 };
+    assert_eq(x, x);
+}

test_programs/execution_success/derive/src/main.nr

@@ -8,7 +8,7 @@ struct MyStruct { my_field: u32 }
 
 comptime fn derive_do_nothing(s: StructDefinition) -> Quoted {
     let typ = s.as_type();
-    let generics = s.generics().join(quote {,});
+    let generics = s.generics().map(|g| quote { $g }).join(quote {,});
     quote {
         impl<$generics> DoNothing for $typ {
             fn do_nothing(_self: Self) {
@@ -21,15 +21,18 @@ comptime fn derive_do_nothing(s: StructDefinition) -> Quoted {
 
 // Test stdlib derive fns & multiple traits
 #[derive(Eq, Default)]
-struct MyOtherStruct {
-    field1: u32,
-    field2: u64,
+struct MyOtherStruct<A, B> {
+    field1: A,
+    field2: B,
 }
 
 fn main() {
     let s = MyStruct { my_field: 1 };
     s.do_nothing();
 
-    let o = MyOtherStruct::default();
+    let o: MyOtherStruct<Field, u32> = MyOtherStruct::default();
+    assert_eq(o, o);
+
+    let o: MyOtherStruct<u8, [str<2>]> = MyOtherStruct::default();
     assert_eq(o, o);
 }