Blanket trait implementations (FuelLabs#4687)

## Description This change allows blanket implementations for traits, i.e.: ```sway impl<T> SomeTrait for T {} ``` As part of this we now import trait implementations that are in the same namespace as an imported trait. Ideally we'd want to import all existing trait implementations this way, but this would require another pass or a query, which is probably out of scope for a first implementation. Traits are deduplicated here using the trait decl span. Fix FuelLabs#4010 ## Checklist - [x] I have linked to any relevant issues. - [x] I have commented my code, particularly in hard-to-understand areas. - [x] I have updated the documentation where relevant (API docs, the reference, and the Sway book). - [x] I have added tests that prove my fix is effective or that my feature works. - [x] I have added (or requested a maintainer to add) the necessary `Breaking*` or `New Feature` labels where relevant. - [x] I have done my best to ensure that my PR adheres to [the Fuel Labs Code Review Standards](https://github.com/FuelLabs/rfcs/blob/master/text/code-standards/external-contributors.md). - [x] I have requested a review from the relevant team or maintainers. Co-authored-by: Joshua Batty <[email protected]>
braveerr · Jun 23, 2023 · 8d467e6 · 8d467e6
1 parent e8d6472
commit 8d467e6
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Showing 15 changed files with 127 additions and 10 deletions.
diff --git a/sway-core/src/semantic_analysis/ast_node/declaration/declaration.rs b/sway-core/src/semantic_analysis/ast_node/declaration/declaration.rs
@@ -188,6 +188,10 @@ impl ty::TyDecl {
                         impl_trait.implementing_for.type_id,
                         &impl_trait.items,
                         &impl_trait.span,
+                        impl_trait
+                            .trait_decl_ref
+                            .as_ref()
+                            .map(|decl_ref| decl_ref.decl_span().clone()),
                         false,
                         engines,
                     ),
@@ -216,6 +220,10 @@ impl ty::TyDecl {
                         impl_trait.implementing_for.type_id,
                         &impl_trait.items,
                         &impl_trait.span,
+                        impl_trait
+                            .trait_decl_ref
+                            .as_ref()
+                            .map(|decl_ref| decl_ref.decl_span().clone()),
                         true,
                         engines,
                     ),

diff --git a/sway-core/src/semantic_analysis/ast_node/declaration/impl_trait.rs b/sway-core/src/semantic_analysis/ast_node/declaration/impl_trait.rs
@@ -140,6 +140,7 @@ impl ty::TyImplTrait {
                         &trait_decl.items,
                         &items,
                         &trait_name,
+                        &trait_decl.span(),
                         &block_span,
                         false,
                     ),
@@ -199,6 +200,7 @@ impl ty::TyImplTrait {
                         &abi.items,
                         &items,
                         &trait_name,
+                        &abi.span(),
                         &block_span,
                         true
                     ),
@@ -394,6 +396,7 @@ fn type_check_trait_implementation(
     trait_items: &[TyImplItem],
     impl_items: &[ImplItem],
     trait_name: &CallPath,
+    trait_decl_span: &Span,
     block_span: &Span,
     is_contract: bool,
 ) -> CompileResult<Vec<TyImplItem>> {
@@ -481,6 +484,7 @@ fn type_check_trait_implementation(
                 .cloned()
                 .collect::<Vec<_>>(),
             &trait_name.span(),
+            Some(trait_decl_span.clone()),
             false,
             engines,
         );

diff --git a/sway-core/src/semantic_analysis/ast_node/declaration/trait.rs b/sway-core/src/semantic_analysis/ast_node/declaration/trait.rs
@@ -146,6 +146,7 @@ impl ty::TyTraitDecl {
                 self_type,
                 &dummy_interface_surface,
                 &span,
+                None,
                 false,
                 engines,
             ),
@@ -409,6 +410,7 @@ impl ty::TyTraitDecl {
             type_id,
             &all_items,
             &trait_name.span(),
+            Some(self.span()),
             false,
             engines,
         );

diff --git a/sway-core/src/semantic_analysis/ast_node/expression/typed_expression.rs b/sway-core/src/semantic_analysis/ast_node/expression/typed_expression.rs
@@ -1560,6 +1560,7 @@ impl ty::TyExpression {
                 return_type,
                 &abi_items,
                 &span,
+                Some(span.clone()),
                 false,
                 engines,
             ),

diff --git a/sway-core/src/semantic_analysis/namespace/module.rs b/sway-core/src/semantic_analysis/namespace/module.rs
@@ -435,6 +435,18 @@ impl Module {
                         engines,
                     );
                 }
+                // if this is a trait, import its implementations
+                let decl_span = decl.span();
+                if let TyDecl::TraitDecl(_) = &decl {
+                    // TODO: we only import local impls from the source namespace
+                    // this is okay for now but we'll need to device some mechanism to collect all available trait impls
+                    impls_to_insert.extend(
+                        src_ns
+                            .implemented_traits
+                            .filter_by_trait_decl_span(decl_span),
+                        engines,
+                    );
+                }
                 // no matter what, import it this way though.
                 let dst_ns = &mut self[dst];
                 let add_synonym = |name| {

diff --git a/sway-core/src/semantic_analysis/namespace/namespace.rs b/sway-core/src/semantic_analysis/namespace/namespace.rs
@@ -2,10 +2,7 @@ use crate::{
     decl_engine::{DeclRefConstant, DeclRefFunction},
     engine_threading::*,
     error::*,
-    language::{
-        ty::{self},
-        CallPath, Visibility,
-    },
+    language::{ty, CallPath, Visibility},
     type_system::*,
     CompileResult, Ident,
 };
@@ -616,6 +613,7 @@ impl Namespace {
         type_id: TypeId,
         items: &[ty::TyImplItem],
         impl_span: &Span,
+        trait_decl_span: Option<Span>,
         is_impl_self: bool,
         engines: &Engines,
     ) -> CompileResult<()> {
@@ -629,6 +627,7 @@ impl Namespace {
             type_id,
             items,
             impl_span,
+            trait_decl_span,
             is_impl_self,
             engines,
         )

diff --git a/sway-core/src/semantic_analysis/namespace/trait_map.rs b/sway-core/src/semantic_analysis/namespace/trait_map.rs
@@ -58,6 +58,7 @@ type TraitName = CallPath<TraitSuffix>;
 struct TraitKey {
     name: TraitName,
     type_id: TypeId,
+    trait_decl_span: Option<Span>,
 }
 
 impl OrdWithEngines for TraitKey {
@@ -112,6 +113,7 @@ impl TraitMap {
         type_id: TypeId,
         items: &[TyImplItem],
         impl_span: &Span,
+        trait_decl_span: Option<Span>,
         is_impl_self: bool,
         engines: &Engines,
     ) -> CompileResult<()> {
@@ -150,6 +152,7 @@ impl TraitMap {
                 TraitKey {
                     name: map_trait_name,
                     type_id: map_type_id,
+                    trait_decl_span: _,
                 },
             value:
                 TraitValue {
@@ -241,7 +244,14 @@ impl TraitMap {
         };
 
         // even if there is a conflicting definition, add the trait anyway
-        self.insert_inner(trait_name, impl_span.clone(), type_id, trait_items, engines);
+        self.insert_inner(
+            trait_name,
+            impl_span.clone(),
+            trait_decl_span,
+            type_id,
+            trait_items,
+            engines,
+        );
 
         if errors.is_empty() {
             ok((), warnings, errors)
@@ -254,13 +264,15 @@ impl TraitMap {
         &mut self,
         trait_name: TraitName,
         impl_span: Span,
+        trait_decl_span: Option<Span>,
         type_id: TypeId,
         trait_methods: TraitItems,
         engines: &Engines,
     ) {
         let key = TraitKey {
             name: trait_name,
             type_id,
+            trait_decl_span,
         };
         let value = TraitValue {
             trait_items: trait_methods,
@@ -381,6 +393,23 @@ impl TraitMap {
         }
     }
 
+    /// Filters the entries in `self` and return a new [TraitMap] with all of
+    /// the entries from `self` that implement a trait from the declaration with that span.
+    pub(crate) fn filter_by_trait_decl_span(&self, trait_decl_span: Span) -> TraitMap {
+        let mut trait_map = TraitMap::default();
+        for entry in self.trait_impls.iter() {
+            if entry
+                .key
+                .trait_decl_span
+                .as_ref()
+                .map_or(false, |span| span == &trait_decl_span)
+            {
+                trait_map.trait_impls.push(entry.clone());
+            }
+        }
+        trait_map
+    }
+
     /// Filters the entries in `self` with the given [TypeId] `type_id` and
     /// return a new [TraitMap] with all of the entries from `self` for which
     /// `type_id` is a subtype. Additionally, the new [TraitMap] contains the
@@ -603,6 +632,7 @@ impl TraitMap {
                 TraitKey {
                     name: map_trait_name,
                     type_id: map_type_id,
+                    trait_decl_span: map_trait_decl_span,
                 },
             value:
                 TraitValue {
@@ -617,6 +647,7 @@ impl TraitMap {
                     trait_map.insert_inner(
                         map_trait_name.clone(),
                         impl_span.clone(),
+                        map_trait_decl_span.clone(),
                         *type_id,
                         map_trait_items.clone(),
                         engines,
@@ -655,6 +686,7 @@ impl TraitMap {
                     trait_map.insert_inner(
                         map_trait_name.clone(),
                         impl_span.clone(),
+                        map_trait_decl_span.clone(),
                         *type_id,
                         trait_items,
                         engines,

diff --git a/sway-core/src/type_system/info.rs b/sway-core/src/type_system/info.rs
@@ -1058,9 +1058,9 @@ impl TypeInfo {
             | TypeInfo::Array(_, _)
             | TypeInfo::Contract
             | TypeInfo::Numeric
-            | TypeInfo::Alias { .. } => ok((), warnings, errors),
+            | TypeInfo::Alias { .. }
+            | TypeInfo::UnknownGeneric { .. } => ok((), warnings, errors),
             TypeInfo::Unknown
-            | TypeInfo::UnknownGeneric { .. }
             | TypeInfo::ContractCaller { .. }
             | TypeInfo::SelfType
             | TypeInfo::Storage { .. }

diff --git a/test/src/e2e_vm_tests/test_programs/should_fail/generic_traits/test.toml b/test/src/e2e_vm_tests/test_programs/should_fail/generic_traits/test.toml
@@ -22,9 +22,6 @@ category = "fail"
 # check: $()}
 # check: $()Conflicting implementations of trait "Multiple<u64>" for type "FooBarData<F>".
 
-# check: $()impl<T> Returner<T> for T {
-# check: $()Unimplemented feature: implementing traits on this type is unsupported right now
-
 # check: $()impl<T> Returner<T> for Self {
 # check: $()Unimplemented feature: implementing traits on this type is unsupported right now
 

diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/Forc.lock b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/Forc.lock
@@ -0,0 +1,3 @@
+[[package]]
+name = 'blanket_impl'
+source = 'member'
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/Forc.toml b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/Forc.toml
@@ -0,0 +1,6 @@
+[project]
+name = "blanket_impl"
+authors = ["Fuel Labs <[email protected]>"]
+entry = "main.sw"
+license = "Apache-2.0"
+implicit-std = false
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/json_abi_oracle.json b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/json_abi_oracle.json
@@ -0,0 +1,25 @@
+{
+  "configurables": [],
+  "functions": [
+    {
+      "attributes": null,
+      "inputs": [],
+      "name": "main",
+      "output": {
+        "name": "",
+        "type": 0,
+        "typeArguments": null
+      }
+    }
+  ],
+  "loggedTypes": [],
+  "messagesTypes": [],
+  "types": [
+    {
+      "components": null,
+      "type": "u64",
+      "typeId": 0,
+      "typeParameters": null
+    }
+  ]
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/src/main.sw b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/src/main.sw
@@ -0,0 +1,14 @@
+script;
+
+mod traits;
+
+use traits::Foo;
+
+struct Bar {}
+
+fn main() -> u64 {
+    let bar = Bar {};
+    bar.foo()
+
+}
+
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/src/traits.sw b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/src/traits.sw
@@ -0,0 +1,11 @@
+library;
+
+pub trait Foo {
+    fn foo(self) -> u64;
+}
+
+impl<T> Foo for T {
+    fn foo(self) -> u64 {
+        42
+    }
+}
diff --git a/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/test.toml b/test/src/e2e_vm_tests/test_programs/should_pass/blanket_impl/test.toml
@@ -0,0 +1,3 @@
+category = "run"
+expected_result = { action = "return", value = 42 }
+validate_abi = true