Merge pull request #442 from nathanwhit/typename-raw-pointer

Add raw pointers to `TypeName`

Author: jackh726

book/src/clauses/well_known_traits.md

@@ -35,6 +35,7 @@ Some common examples of auto traits are `Send` and `Sync`.
 | scalar types    | 📚    | 📚    | ✅     | ⚬     | ⚬   |  ⚬  |  ⚬     |  ⚬       |    ❌        |
 | trait objects   | ⚬    | ⚬    | ⚬     |  ✅    | ⚬    | ⚬   | ⚬      |  ⚬       |    ⚬        |
 | functions ptrs  | ✅    | ✅    | ✅     | ⚬     | ⚬    | ❌   | ⚬      |  ⚬       |    ❌         |
+| raw ptrs        | ✅   |  ✅  |   ✅   |  ⚬    |   ⚬   |  ⚬  |   ⚬    |   ⚬      |      ❌      |
 | arrays❌         | ❌     | ❌    | ❌     | ❌      | ⚬   | ⚬   | ⚬      |  ⚬       |    ❌        |
 | slices❌         | ❌     | ❌    | ⚬     | ❌      | ⚬   | ⚬   | ⚬      |  ⚬       |    ❌       |
 | closures❌       | ❌     | ❌    | ❌     | ⚬      | ⚬   | ❌   | ⚬      |  ⚬       |    ❌        |

chalk-integration/src/lowering.rs

@@ -1210,6 +1210,17 @@ impl LowerTy for Ty {
                 substitution: chalk_ir::Substitution::empty(interner),
             })
             .intern(interner)),
+
+            Ty::Raw { mutability, ty } => Ok(chalk_ir::TyData::Apply(chalk_ir::ApplicationTy {
+                name: chalk_ir::TypeName::Raw(ast_mutability_to_chalk_mutability(
+                    mutability.clone(),
+                )),
+                substitution: chalk_ir::Substitution::from_fallible(
+                    interner,
+                    std::iter::once(Ok(ty.lower(env)?)),
+                )?,
+            })
+            .intern(interner)),
         }
     }
 }
@@ -1591,3 +1602,10 @@ fn ast_scalar_to_chalk_scalar(scalar: ScalarType) -> chalk_ir::Scalar {
         ScalarType::Char => chalk_ir::Scalar::Char,
     }
 }
+
+fn ast_mutability_to_chalk_mutability(mutability: Mutability) -> chalk_ir::Mutability {
+    match mutability {
+        Mutability::Mut => chalk_ir::Mutability::Mut,
+        Mutability::Not => chalk_ir::Mutability::Not,
+    }
+}

chalk-ir/src/debug.rs

@@ -144,6 +144,7 @@ impl<I: Interner> Debug for TypeName<I> {
             TypeName::Scalar(scalar) => write!(fmt, "{:?}", scalar),
             TypeName::Tuple(arity) => write!(fmt, "{:?}", arity),
             TypeName::OpaqueType(opaque_ty) => write!(fmt, "!{:?}", opaque_ty),
+            TypeName::Raw(mutability) => write!(fmt, "{:?}", mutability),
             TypeName::Error => write!(fmt, "{{error}}"),
         }
     }

chalk-ir/src/fold/boring_impls.rs

@@ -248,6 +248,7 @@ copy_fold!(IntTy);
 copy_fold!(FloatTy);
 copy_fold!(Scalar);
 copy_fold!(ClausePriority);
+copy_fold!(Mutability);
 
 #[macro_export]
 macro_rules! id_fold {

chalk-ir/src/lib.rs

@@ -136,6 +136,12 @@ pub enum Scalar {
     Float(FloatTy),
 }
 
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum Mutability {
+    Mut,
+    Not,
+}
+
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Fold, Visit)]
 pub enum TypeName<I: Interner> {
     /// a type like `Vec<T>`
@@ -150,6 +156,9 @@ pub enum TypeName<I: Interner> {
     /// a tuple of the given arity
     Tuple(usize),
 
+    /// a raw pointer type like `*const T` or `*mut T`
+    Raw(Mutability),
+
     /// a placeholder for opaque types like `impl Trait`
     OpaqueType(OpaqueTyId<I>),
 

chalk-ir/src/visit/boring_impls.rs

@@ -6,9 +6,9 @@
 
 use crate::{
     AssocTypeId, ClausePriority, DebruijnIndex, FloatTy, Goals, ImplId, IntTy, Interner,
-    OpaqueTyId, Parameter, ParameterKind, PlaceholderIndex, ProgramClause, ProgramClauseData,
-    ProgramClauses, QuantifiedWhereClauses, QuantifierKind, Scalar, StructId, Substitution,
-    SuperVisit, TraitId, UintTy, UniverseIndex, Visit, VisitResult, Visitor,
+    Mutability, OpaqueTyId, Parameter, ParameterKind, PlaceholderIndex, ProgramClause,
+    ProgramClauseData, ProgramClauses, QuantifiedWhereClauses, QuantifierKind, Scalar, StructId,
+    Substitution, SuperVisit, TraitId, UintTy, UniverseIndex, Visit, VisitResult, Visitor,
 };
 use chalk_engine::{context::Context, ExClause, FlounderedSubgoal, Literal};
 use std::{marker::PhantomData, sync::Arc};
@@ -211,6 +211,7 @@ const_visit!(Scalar);
 const_visit!(UintTy);
 const_visit!(IntTy);
 const_visit!(FloatTy);
+const_visit!(Mutability);
 
 #[macro_export]
 macro_rules! id_visit {

chalk-parse/src/ast.rs

@@ -193,6 +193,10 @@ pub enum Ty {
     Scalar {
         ty: ScalarType,
     },
+    Raw {
+        mutability: Mutability,
+        ty: Box<Ty>,
+    },
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug)]
@@ -230,6 +234,12 @@ pub enum ScalarType {
     Float(FloatTy),
 }
 
+#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+pub enum Mutability {
+    Mut,
+    Not,
+}
+
 #[derive(Clone, PartialEq, Eq, Debug)]
 pub enum Lifetime {
     Id { name: Identifier },

chalk-parse/src/parser.lalrpop

@@ -205,6 +205,7 @@ TyWithoutFor: Ty = {
     <n:Id> "<" <a:Comma<Parameter>> ">" => Ty::Apply { name: n, args: a },
     <p:ProjectionTy> => Ty::Projection { proj: p },
     "(" <t:TupleOrParensInner> ")" => t,
+    "*" <m: Mutability> <t:Ty> => Ty::Raw{ mutability: m, ty: Box::new(t) },
 };
 
 ScalarType: ScalarType = {
@@ -237,6 +238,11 @@ TupleOrParensInner: Ty = {
     () => Ty::Tuple { types: vec![] },
 };
 
+Mutability: Mutability = {
+    "mut" => Mutability::Mut,
+    "const" => Mutability::Not,
+};
+
 Lifetime: Lifetime = {
     <n:LifetimeId> => Lifetime::Id { name: n },
 };

chalk-solve/src/clauses.rs

@@ -410,6 +410,7 @@ fn match_type_name<I: Interner>(
         TypeName::Tuple(_) => {
             builder.push_fact(WellFormed::Ty(application.clone().intern(interner)))
         }
+        TypeName::Raw(_) => builder.push_fact(WellFormed::Ty(application.clone().intern(interner))),
     }
 }
 

chalk-solve/src/clauses/builtin_traits/copy.rs

@@ -41,6 +41,7 @@ pub fn add_copy_program_clauses<I: Interner>(
             TypeName::Tuple(arity) => {
                 push_tuple_copy_conditions(db, builder, trait_ref, *arity, substitution)
             }
+            TypeName::Raw(_) => builder.push_fact(trait_ref.clone()),
             _ => return,
         },
         TyData::Function(_) => builder.push_fact(trait_ref.clone()),

chalk-solve/src/clauses/builtin_traits/sized.rs

@@ -75,6 +75,7 @@ pub fn add_sized_program_clauses<I: Interner>(
             TypeName::Tuple(arity) => {
                 push_tuple_sized_conditions(db, builder, trait_ref, *arity, substitution)
             }
+            TypeName::Raw(_) => builder.push_fact(trait_ref.clone()),
             _ => return,
         },
         TyData::Function(_) => builder.push_fact(trait_ref.clone()),

tests/lowering/mod.rs

@@ -471,7 +471,41 @@ fn scalars() {
         }
 
         error_msg {
-            "parse error: UnrecognizedToken { token: (8, Token(49, \"i32\"), 11), expected: [\"r#\\\"([A-Za-z]|_)([A-Za-z0-9]|_)*\\\"#\"] }"
+            "parse error: UnrecognizedToken { token: (8, Token(51, \"i32\"), 11), expected: [\"r#\\\"([A-Za-z]|_)([A-Za-z0-9]|_)*\\\"#\"] }"
+        }
+    }
+}
+
+#[test]
+fn raw_pointers() {
+    lowering_success! {
+        program {
+            trait Quux { }
+            struct Foo<T> { a: *const T }
+
+            struct Bar<T> { a: *mut T }
+
+            impl<T> Quux for Foo<*mut T> { }
+            impl<T> Quux for Bar<*const T> { }
+        }
+    }
+
+    lowering_error! {
+        program {
+            struct *const i32 { }
+        }
+        error_msg {
+            "parse error: UnrecognizedToken { token: (8, Token(7, \"*\"), 9), expected: [\"r#\\\"([A-Za-z]|_)([A-Za-z0-9]|_)*\\\"#\"] }"
+        }
+    }
+
+    lowering_error! {
+        program {
+            trait Foo { }
+            impl Foo for *i32 { }
+        }
+        error_msg {
+            "parse error: UnrecognizedToken { token: (30, Token(51, \"i32\"), 33), expected: [\"\\\"const\\\"\", \"\\\"mut\\\"\"] }"
         }
     }
 }