Unique trait id as a parameter for CallBuilder trait impls (#1141)

* Copy multiple foreign traits example from other PR * Rename to TraitInfo and add ID const * Use TraitInfo::ID to resolve CallBuilder impl * clean up todos and docs * clippy * Fix message selector overlap UI tests * Update examples/trait-incrementer/Cargo.toml Co-authored-by: Hernando Castano <[email protected]> * Update examples/trait-incrementer/Cargo.toml Co-authored-by: Hernando Castano <[email protected]> * Update examples/trait-incrementer/traits/lib.rs Co-authored-by: Hernando Castano <[email protected]> * Update examples/trait-incrementer/traits/Cargo.toml Co-authored-by: Hernando Castano <[email protected]> * Update examples/trait-incrementer/traits/Cargo.toml Co-authored-by: Hernando Castano <[email protected]> Co-authored-by: Hernando Castano <[email protected]>
use-ink · Feb 21, 2022 · 2f86746 · 2f86746
1 parent 9fd0317
commit 2f86746
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Showing 16 changed files with 153 additions and 41 deletions.
diff --git a/crates/lang/codegen/src/generator/arg_list.rs b/crates/lang/codegen/src/generator/arg_list.rs
@@ -98,7 +98,7 @@ pub fn generate_reference_to_trait_info(
     trait_path: &syn::Path,
 ) -> TokenStream2 {
     quote_spanned!(span=>
-        <::ink_lang::reflect::TraitDefinitionRegistry<Environment>
-            as #trait_path>::__ink_TraitInfo
+        <<::ink_lang::reflect::TraitDefinitionRegistry<Environment>
+            as #trait_path>::__ink_TraitInfo as ::ink_lang::reflect::TraitInfo>::ID
     )
 }
diff --git a/crates/lang/codegen/src/generator/as_dependency/call_builder.rs b/crates/lang/codegen/src/generator/as_dependency/call_builder.rs
@@ -182,10 +182,10 @@ impl CallBuilder<'_> {
     ) -> TokenStream2 {
         let span = impl_block.span();
         let cb_ident = Self::call_builder_ident();
-        let trait_info = generator::generate_reference_to_trait_info(span, trait_path);
+        let trait_info_id = generator::generate_reference_to_trait_info(span, trait_path);
         quote_spanned!(span=>
             #[doc(hidden)]
-            impl ::ink_lang::codegen::TraitCallForwarderFor<#trait_info> for #cb_ident {
+            impl ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}> for #cb_ident {
                 type Forwarder = <<Self as #trait_path>::__ink_TraitInfo as ::ink_lang::codegen::TraitCallForwarder>::Forwarder;
 
                 #[inline]
@@ -217,7 +217,7 @@ impl CallBuilder<'_> {
                 #[inline]
                 fn build(&self) -> &<Self::Forwarder as ::ink_lang::codegen::TraitCallBuilder>::Builder {
                     <_ as ::ink_lang::codegen::TraitCallBuilder>::call(
-                        <Self as ::ink_lang::codegen::TraitCallForwarderFor<#trait_info>>::forward(self)
+                        <Self as ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}>>::forward(self)
                     )
                 }
 
@@ -226,7 +226,7 @@ impl CallBuilder<'_> {
                     -> &mut <Self::Forwarder as ::ink_lang::codegen::TraitCallBuilder>::Builder
                 {
                     <_ as ::ink_lang::codegen::TraitCallBuilder>::call_mut(
-                        <Self as ::ink_lang::codegen::TraitCallForwarderFor<#trait_info>>::forward_mut(self)
+                        <Self as ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}>>::forward_mut(self)
                     )
                 }
             }
@@ -265,7 +265,7 @@ impl CallBuilder<'_> {
         let span = message.span();
         let message_ident = message.ident();
         let output_ident = generator::output_ident(message_ident);
-        let trait_info = generator::generate_reference_to_trait_info(span, trait_path);
+        let trait_info_id = generator::generate_reference_to_trait_info(span, trait_path);
         let (input_bindings, input_types): (Vec<_>, Vec<_>) = message
             .callable()
             .inputs()
@@ -283,7 +283,7 @@ impl CallBuilder<'_> {
         quote_spanned!(span=>
             type #output_ident = <<<
                 Self
-                as ::ink_lang::codegen::TraitCallForwarderFor<#trait_info>>::Forwarder
+                as ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}>>::Forwarder
                 as ::ink_lang::codegen::TraitCallBuilder>::Builder
                 as #trait_path>::#output_ident;
 
@@ -294,7 +294,7 @@ impl CallBuilder<'_> {
                 #( , #input_bindings: #input_types )*
             ) -> Self::#output_ident {
                 <_ as #trait_path>::#message_ident(
-                    <Self as ::ink_lang::codegen::TraitCallForwarderFor<#trait_info>>::#build_cmd(self)
+                    <Self as ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}>>::#build_cmd(self)
                     #( , #input_bindings )*
                 )
             }

diff --git a/crates/lang/codegen/src/generator/as_dependency/contract_ref.rs b/crates/lang/codegen/src/generator/as_dependency/contract_ref.rs
@@ -242,7 +242,7 @@ impl ContractRef<'_> {
     ) -> TokenStream2 {
         use ir::Callable as _;
         let span = message.span();
-        let trait_info = generator::generate_reference_to_trait_info(span, trait_path);
+        let trait_info_id = generator::generate_reference_to_trait_info(span, trait_path);
         let message_ident = message.ident();
         let output_ident = generator::output_ident(message_ident);
         let call_operator = match message.receiver() {
@@ -266,7 +266,7 @@ impl ContractRef<'_> {
                 #( , #input_bindings : #input_types )*
             ) -> Self::#output_ident {
                 <_ as #trait_path>::#message_ident(
-                    <_ as ::ink_lang::codegen::TraitCallForwarderFor<#trait_info>>::#forward_operator(
+                    <_ as ::ink_lang::codegen::TraitCallForwarderFor<{#trait_info_id}>>::#forward_operator(
                         <Self as ::ink_lang::codegen::TraitCallBuilder>::#call_operator(self),
                     )
                     #( , #input_bindings )*

diff --git a/crates/lang/codegen/src/generator/trait_def/trait_registry.rs b/crates/lang/codegen/src/generator/trait_def/trait_registry.rs
@@ -243,6 +243,7 @@ impl TraitRegistry<'_> {
     /// It is mainly used to access global information about the ink! trait.
     fn generate_trait_info_object(&self) -> TokenStream2 {
         let span = self.span();
+        let trait_id = self.generate_trait_id();
         let trait_ident = self.trait_ident();
         let trait_info_ident = self.trait_def.trait_info_ident();
         let trait_call_forwarder = self.trait_def.call_forwarder_ident();
@@ -256,10 +257,12 @@ impl TraitRegistry<'_> {
 
             #trait_message_info
 
-            impl<E> ::ink_lang::reflect::TraitModulePath for #trait_info_ident<E>
+            impl<E> ::ink_lang::reflect::TraitInfo for #trait_info_ident<E>
             where
                 E: ::ink_env::Environment,
             {
+                const ID: u32 = #trait_id;
+
                 const PATH: &'static ::core::primitive::str = ::core::module_path!();
 
                 const NAME: &'static ::core::primitive::str = ::core::stringify!(#trait_ident);
@@ -274,6 +277,25 @@ impl TraitRegistry<'_> {
         )
     }
 
+    /// Generates a unique id for the trait, as an XOR of the set of selectors.
+    fn generate_trait_id(&self) -> syn::LitInt {
+        let span = self.span();
+        let mut id = 0u32;
+        debug_assert!(
+            self.trait_def
+                .trait_def
+                .item()
+                .iter_items()
+                .next()
+                .is_some(),
+            "invalid empty ink! trait definition"
+        );
+        for (_, selector) in self.trait_def.trait_def.item().iter_items() {
+            id ^= selector.into_be_u32()
+        }
+        syn::LitInt::new(&format!("{}", id), span)
+    }
+
     /// Generates the [`::ink_lang::reflect::TraitMessageInfo`] implementations for all
     /// ink! messages defined by the ink! trait definition.
     fn generate_info_for_trait_messages(&self) -> TokenStream2 {

diff --git a/crates/lang/src/codegen/trait_def/call_builder.rs b/crates/lang/src/codegen/trait_def/call_builder.rs
@@ -48,7 +48,7 @@ pub trait TraitCallForwarder {
 /// While the trait is not necessary it encapsulates a lot of
 /// utility and auxiliary code required for the actual ink! trait
 /// implementations.
-pub trait TraitCallForwarderFor<TraitInfo> {
+pub trait TraitCallForwarderFor<const TRAIT_ID: u32> {
     type Forwarder: TraitCallBuilder;
 
     /// Forwards the `&self` call.

diff --git a/crates/lang/src/reflect/mod.rs b/crates/lang/src/reflect/mod.rs
@@ -49,7 +49,7 @@ pub use self::{
     event::ContractEventBase,
     trait_def::{
         TraitDefinitionRegistry,
+        TraitInfo,
         TraitMessageInfo,
-        TraitModulePath,
     },
 };
diff --git a/crates/lang/src/reflect/trait_def/info.rs b/crates/lang/src/reflect/trait_def/info.rs
@@ -136,11 +136,11 @@ pub trait TraitMessageInfo<const TRAIT_LOCAL_MESSAGE_ID: u32> {
     const SELECTOR: [u8; 4];
 }
 
-/// Captures the module path of the ink! trait definition.
-///
-/// This can be used to differentiate between two equally named
-/// ink! trait definitions and also for metadata.
-pub trait TraitModulePath {
+/// Captures info about an ink! trait definition.
+pub trait TraitInfo {
+    /// The unique id of the ink! trait definition.
+    const ID: u32;
+
     /// The module path of the ink! trait definition.
     ///
     /// This is equivalent to Rust's builtin `module_path!` macro

diff --git a/crates/lang/src/reflect/trait_def/mod.rs b/crates/lang/src/reflect/trait_def/mod.rs
@@ -17,8 +17,8 @@ mod registry;
 
 pub use self::{
     info::{
+        TraitInfo,
         TraitMessageInfo,
-        TraitModulePath,
     },
     registry::TraitDefinitionRegistry,
 };
diff --git a/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-1.stderr b/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-1.stderr
@@ -6,3 +6,12 @@ error[E0119]: conflicting implementations of trait `ink_lang::reflect::Dispatcha
 ...
 47 |         fn message(&self) {}
    |         ^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::Contract`
+
+error[E0119]: conflicting implementations of trait `ink_lang::codegen::TraitCallForwarderFor<1083895717_u32>` for type `contract::_::CallBuilder`
+  --> tests/ui/contract/fail/trait-message-selector-overlap-1.rs:45:5
+   |
+40 |     impl TraitDefinition1 for Contract {
+   |     ---------------------------------- first implementation here
+...
+45 |     impl TraitDefinition2 for Contract {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::_::CallBuilder`
diff --git a/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-2.stderr b/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-2.stderr
@@ -6,3 +6,12 @@ error[E0119]: conflicting implementations of trait `ink_lang::reflect::Dispatcha
 ...
 47 |         fn message(&self) {}
    |         ^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::Contract`
+
+error[E0119]: conflicting implementations of trait `ink_lang::codegen::TraitCallForwarderFor<1518209067_u32>` for type `contract::_::CallBuilder`
+  --> tests/ui/contract/fail/trait-message-selector-overlap-2.rs:45:5
+   |
+40 |     impl TraitDefinition1 for Contract {
+   |     ---------------------------------- first implementation here
+...
+45 |     impl TraitDefinition2 for Contract {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::_::CallBuilder`
diff --git a/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-3.stderr b/crates/lang/tests/ui/contract/fail/trait-message-selector-overlap-3.stderr
@@ -6,3 +6,12 @@ error[E0119]: conflicting implementations of trait `ink_lang::reflect::Dispatcha
 ...
 47 |         fn message2(&self) {}
    |         ^^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::Contract`
+
+error[E0119]: conflicting implementations of trait `ink_lang::codegen::TraitCallForwarderFor<42_u32>` for type `contract::_::CallBuilder`
+  --> tests/ui/contract/fail/trait-message-selector-overlap-3.rs:45:5
+   |
+40 |     impl TraitDefinition1 for Contract {
+   |     ---------------------------------- first implementation here
+...
+45 |     impl TraitDefinition2 for Contract {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ conflicting implementation for `contract::_::CallBuilder`
diff --git a/examples/trait-incrementer/Cargo.toml b/examples/trait-incrementer/Cargo.toml
@@ -13,6 +13,7 @@ ink_lang = { version = "3.0.0-rc8", path = "../../crates/lang", default-features
 
 scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
 scale-info = { version = "2", default-features = false, features = ["derive"], optional = true }
+traits = { path = "./traits", default-features = false }
 
 [lib]
 name = "trait_incrementer"
@@ -29,5 +30,6 @@ std = [
     "ink_lang/std",
     "scale/std",
     "scale-info/std",
+    "traits/std",
 ]
 ink-as-dependency = []
diff --git a/examples/trait-incrementer/lib.rs b/examples/trait-incrementer/lib.rs
@@ -3,29 +3,9 @@
 
 use ink_lang as ink;
 
-/// Allows to increment and get the current value.
-#[ink::trait_definition]
-pub trait Increment {
-    /// Increments the current value of the implementer by one (1).
-    #[ink(message)]
-    fn inc(&mut self);
-
-    /// Returns the current value of the implementer.
-    #[ink(message)]
-    fn get(&self) -> u64;
-}
-
-/// Allows to reset the current value.
-#[ink::trait_definition]
-pub trait Reset {
-    /// Resets the current value to zero.
-    #[ink(message)]
-    fn reset(&mut self);
-}
-
 #[ink::contract]
 pub mod incrementer {
-    use super::{
+    use traits::{
         Increment,
         Reset,
     };

diff --git a/examples/trait-incrementer/traits/.gitignore b/examples/trait-incrementer/traits/.gitignore
@@ -0,0 +1,9 @@
+# Ignore build artifacts from the local tests sub-crate.
+/target/
+
+# Ignore backup files creates by cargo fmt.
+**/*.rs.bk
+
+# Remove Cargo.lock when creating an executable, leave it for libraries
+# More information here http://doc.crates.io/guide.html#cargotoml-vs-cargolock
+Cargo.lock
diff --git a/examples/trait-incrementer/traits/Cargo.toml b/examples/trait-incrementer/traits/Cargo.toml
@@ -0,0 +1,33 @@
+[package]
+name = "traits"
+version = "3.0.0-rc8"
+authors = ["Parity Technologies <[email protected]>"]
+edition = "2021"
+
+[dependencies]
+ink_primitives = { version = "3.0.0-rc8", path = "../../../crates/primitives", default-features = false }
+ink_metadata = { version = "3.0.0-rc8", path = "../../../crates/metadata", default-features = false, features = ["derive"], optional = true }
+ink_env = { version = "3.0.0-rc8", path = "../../../crates/env", default-features = false }
+ink_storage = { version = "3.0.0-rc8", path = "../../../crates/storage", default-features = false }
+ink_lang = { version = "3.0.0-rc8", path = "../../../crates/lang", default-features = false }
+
+scale = { package = "parity-scale-codec", version = "3", default-features = false, features = ["derive"] }
+scale-info = { version = "2", default-features = false, features = ["derive"], optional = true }
+
+[lib]
+name = "traits"
+path = "lib.rs"
+crate-type = ["rlib"]
+
+[features]
+default = ["std"]
+std = [
+    "ink_primitives/std",
+    "ink_metadata/std",
+    "ink_env/std",
+    "ink_storage/std",
+    "ink_lang/std",
+    "scale/std",
+    "scale-info/std",
+]
+ink-as-dependency = []
diff --git a/examples/trait-incrementer/traits/lib.rs b/examples/trait-incrementer/traits/lib.rs
@@ -0,0 +1,39 @@
+// Copyright 2018-2022 Parity Technologies (UK) Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#![cfg_attr(not(feature = "std"), no_std)]
+
+//! Traits are extracted into a separate crate to show how the user can import
+//! several foreign traits and implement those for the contract.
+
+use ink_lang as ink;
+
+/// Allows to increment and get the current value.
+#[ink::trait_definition]
+pub trait Increment {
+    /// Increments the current value of the implementer by one (1).
+    #[ink(message)]
+    fn inc(&mut self);
+
+    /// Returns the current value of the implementer.
+    #[ink(message)]
+    fn get(&self) -> u64;
+}
+
+/// Allows to reset the current value.
+#[ink::trait_definition]
+pub trait Reset {
+    /// Resets the current value to zero.
+    #[ink(message)]
+    fn reset(&mut self);
+}